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THE 



PRINCIPLES AND PRACTICE 



OF 



PERIMETRY 



BY 
LUTHER C. PETER, A.M., M.D., F.A.C.S. 

ASSOCIATE PROFESSOR OF OPHTHALMOLOGY, PHILADELPHIA POLYCLINIC AND COLLEGE FOR 

GRADUATES IN MEDICINE; OPHTHALMOLOGIST TO THE RUSH HOSPITAL 

FOR CONSUMPTION AND ALLIED DISEASES 



ILLUSTRATED WITH 119 ENGRAVINGS 




LEA & FEBIGER 

PHILADELPHIA AND NEW YORK 

I 91 6 






Entered according to the Act of Congress, in the year 1916, by 

LEA & FEBIGER, 
in the Office of the Librarian of Congress. All rights reserved. 




MAR 18 1916 

©CI.A428196 



^ 



THESE PAGES 

ARE AFFECTIONATELY DEDICATED 

TO MY 

MOTHER 



PREFACE. 



This book has been written with a twofold object 
in view: (i) to give to the student in ophthalmology 
and ophthalmoneurology a collective study of the 
perimeter and its application, and (2) to stimulate, 
if possible, greater interest in the practice of perimetry. 

It is a fact to be regretted that, although our text- 
books on ophthalmology treat the subject of perimetry 
with due consideration from the standpoint of its clini- 
cal value and application as an aid in diagnosis, few 
authors devote sufficient space to the fundamentals 
of perimetry, to the normal field, the methods of taking 
fields, and the general pathology of the field, to enable 
the student to acquire a good knowledge of the subject. 

So far as I have been able to learn, there is not a 
single volume in the English language devoted entirely 
to perimetry; and with the exception of the excellent 
chapter by Wilbrand in the System of Diseases of the 
Eye, by Norris and Oliver, a complete collective study 
has not appeared in the English language. The volumes 
of Ole Bull and Karl Baas in the German language 
are well known. 

To present, therefore, to the student a systematic 
study of perimetry, its principles and practice, has been 
my first . inspiration in writing this volume. 

A second inspiration in offering this book to the 
profession is the hope that it may be the means, in 
a small way at least, of stimulating interest in the 
minute study of the visual field as a refinement in diag- 
nosis. When we recall the facts that the ophthalmo- 



vi PREFACE 

scope often fails to reveal minute changes in disease 
of the anterior part of the visual path, as for example, 
in beginning toxic amblyopia and forms of retrobulbar 
neuritis; that in disease of the visual path posterior 
to the chiasm, eye-ground changes are late phenomena, 
and that disease above the primary optic centers may 
not be visible at any time by means of the ophthal- 
moscope; that in choriodal disease and in disease of 
the neuro-epithelial layer of the retina, color changes 
differ materially from those observed in disease of the 
nerve-element layers of the retina; that central vision 
may be well preserved in glaucoma while indirect 
vision has almost disappeared, we can hardly fail to 
be impressed with the value of carefully practised 
perimetry as an aid to diagnosis and prognosis. 

The text as presented is, in substance and arrange- 
ment, the course of lectures which I give to the students 
in ophthalmology in the Philadelphia Polyclinic and 
College for Graduates in Medicine. Exception may 
be taken to the order in which I have treated the 
various subdivisions. It is, however, the order which 
has been most helpful to the student in grasping the 
subject. The methods employed and the proper use 
of the instruments follow naturally after the explana- 
tion of the fundamental laws which govern the pro- 
jected field and establish the normal size and character 
of the form and color fields. On the other hand, some 
knowledge of the anatomy of the visual tract and the 
physiology of vision must necessarily precede a study 
of the changes which take place in disturbance of 
structure and function of the visual path. Dove- 
tailing, therefore, of the practical and academic has 
been found to be the logical method of presenting the 
subject of perimetry to the student body. 

The treatise is not exhaustive. On the other hand, 
I have endeavored to state concisely and briefly many 



PREFACE vii 

of the elementary facts which need neither amplifica- 
tion nor verification because they have been accepted 
by the medical profession as established facts. In 
the matter of instruments, it is impossible to do justice 
in so small a treatise to all the valuable instruments 
and modifications of the perimeter, and an effort has 
been made to confine the subject matter of the book in 
general to what I feel is essential to the correct use and 
application of the perimeter. 

I trust, therefore, that the student in ophthal- 
mology will not only find in it a foundation for a good 
working knowledge of the perimeter, but that he may 
also find it helpful as a book of reference. 

Public acknowledgment is due my friend and coun- 
sellor, Dr. Wendell Reber, for his helpful suggestions 
from time to time, and for his courtesy in placing at 
my disposal much of the clinical material used in the 
illustrations. 

L. C. P. 

Philadelphia, 1916. 



TABLE OF CONTENTS. 



PART I. 

INTRODUCTORY. 

Definition 17 

Central and Indirect Vision 17 

Visual Acuity 18 

Entopic Study 19 

Laws of Projection and Direction 19 

Corresponding Retinal Points , 20 

Factors which Influence the Size and Shape of the Normal Field . . 22 

Bony Prominences of the Face and Orbital Cavity 23 

Activity of the Retina . . - 23 

Width of the Palpebral Fissure 24 

Size of the Pupil 24 

Refractive Errors 24 

Forward Attachment of the Retina on the Nasal Side .... 24 

Intelligence of the Patient 24 

Influence of Drugs 25 

Fatigue . 25 

Effects of Light 25 

Extent of Normal Form Fields 26 

Size of Color Fields 27 

Color Vision Present Throughout Form Field 29 

Mariotte's Blind Spot . . 29 

Normal Binocular Fields 30 



PART II. 

METHODS. OF EXAMINING FIELDS. AUTOPERIMETRY AND 
PERIMETRY. INSTRUMENTS EMPLOYED. 

Autoperimetry and Perimetry 32 

Methods of Taking Fields 33 

Hand Method 33 

Campimetric Method 35 

Method of Drawing Circles on Blackboard 37 



x TABLE OF CONTENTS 

Methods of Taking Fields — Campimetric Method — 

Practical Use of Campimeter 40 

Color Examination 42 

Examination for Scotoma 43 

Scotomata in Imperfect Fixation 46 

Advantages and Disadvantages in Use of the Campimeter . 48 

Measuring of Light Projection . 49 

Author's Hand Campimeter 49 

Tangent Curtain of Duane 52 

The Perimeter 55 

Forster's Perimeter 55 

Self -registering Perimeter 56 

Reber's Umbrella Perimeter 58 

Bedside and Hand Perimeter 59 

Holth's Chord Perimeter 60 

Artificially Lighted Perimeter 60 

Scotometer • 61 

Charts and Methods of Charting 61 

Recording of Fields Taken on a Non-registering Perimeter ... 63 

Campimetric Charts 64 

Data to be Recorded on Charts 64 

Charts for Binocular Examination of the Fields of Vision by Means 

of the Stereoscope 64 



PART III. 

ANATOMY AND PHYSIOLOGY OF THE VISUAL TRACT. 

Anatomy 66 

Rods and Cones 67 

Blood Supply of the Retina 67 

The Optic Nerve ..." 68 

Papillomacular Bundle 70 

The Chiasm 71 

Optic Tracts 72 

Primary Optic Centers 72 

External Geniculate Body 72 

Anterior Corpora Quadrigemina 72 

Pulvinar 72 

Communication of Primary Optic Centers with the Motor Nerves 

of the Eye 73 

Paths to the Brain 74 

The Cuneus 75 

Physiology of Vision 76 

Physicochemical Phase 76 

Accomodation 77 

Rod and Cone Layers 77 

Physiologic Phase 79 

Psychologic Phase 80 



TABLE OF CONTENTS xr 
PART IV. 

GENERAL PATHOLOGY OF THE VISUAL FIELD. 

Scotomata 82 

Relative and Absolute 82 

Indistinct 83 

Positive and Negative t 84 

Central, Paracentral and Peripheral 85 

Enlargement of Normal Blind Spot of Mariotte 85 

Ring Scotomata 86 

Quadrant and Hemianopic Scotomata — Anopsias 89 

Line of Demarcation . 90 

Overshot Fields, Significance of 92 

Incomplete Hemianopsia 93 

Scotomata Associated with Peripheral Field Changes ... 93 

Changes in Form and Color Fields 94 

Concentrically Contracted Field " . . 94 

Concentric Contraction plus Unequal Defects 95 

Normal Field with Reentering Angle 96 

Changes Peculiar to Colors 97 

Inversion of Color Fields 98 

Tubular Fields •. . . , 99 

Fatigue Field 100 

Scintillating Scotomata 101 



PART V. 

SPECIAL PATHOLOGY OF FIELDS. 

Disease of the Intra-ocular Portion of the Visual Tract 102 

Choroiditis . 104 

Idiopathic Nyctalopia 106 

Idiopathic Hemeralopia 107 

Retinitis 107 

Syphilitic 110 

Nephritic Ill 

Diabetic 114 

Leukemic 114 

Hodgkin's Disease 115 

Solar and Electric Retinitis 115 

Retinitis Pigmentosa . . 118 

Detachment of Retina 121 

Commotio Retinae 124 

Traumatic Anesthesia of Retina 126 

Traumatic Hole in Macula 126 

Rupture of Choroid and Retina 126 



xii TABLE OF CONTENTS 

Disease of the Intra-ocular Portion of the Visual Tract — Retinitis — 

Embolism and Thrombosis of Central Artery of Retina . . 127 

Thrombosis of Retinal Veins 129 

Fields in Retinal Anemia from Hemorrhage in Remote Parts of 

the Body 130 

Coloboma of Choroid and Retina 130 

Coloboma of Optic Nerve .131 

Coloboma of Macula 132 

Persistent Medullated Nerve Fibers 132 

Wounds of the Retina 133 

Diseases of the Papilla or Intra-ocular Part of the Optic Nerve . . 134 

Choked Disc — Papillitis or Papilledema 134 

Visual Fields in Glaucoma 138 

Type of Changes 138 

Bjerrum's Symptom 143 

Disease of Optic Nerve Proper 144 

Optic Neuritis 145 

Diffuse Interstitial and Perineuritis 145 

Field Changes in Posterior Accessory Sinus Disease . . . 147 

True Retrobulbar Neuritis 150 

Acute Retrobulbar Neuritis 151 

Toxic Amblyopia or Chronic Retrobulbar Neuritis . . 151 

Optic Nerve Atrophy 155 

Primary Optic Atrophy 156 

Tabes Dorsalis 156 

Insular Sclerosis and Paresis . . . ... . . . 157 

Paralysis Agitans 1,58 

Chronic Myelitis. Spastic Paraplegia. Syringomyelia . 158 

Bulbar Paralysis 158 

Friedreich's Ataxia 159 

Leber's Disease 159 

Embolism and Thrombosis of Central Artery of the Retina 161 

Secondary Atrophy . 162 

Postneuritic or Consecutive Atrophy 162 

Optic Atrophy following Disease of the Choroid and Retina . 165 

Disease of the Chiasm 165 

Types of Hemianopsia 166 

Bitemporal. Binasal. Altitudinal 166 

Central Amblyopia 176 

Fields in Disease of Optic Tracts and Primary Optic Centers . . . 177 

Atrophy in Disease of the Tracts . * 177 

Wernicke's Pupillary Phenomenon 178 

Wilbrand's Prism Phenomenon 178 

Crossed Amblyopia 180 

Disease of the Optic Radiations 182 

Color Anopsias 183 

Location of Higher Centers 184 



TABLE OF CONTENTS xiii 



PART VI. 

FIELDS IN FUNCTIONAL NERVOUS DISEASES. 

Classification 190 

Hysteria 191 

Concentric Contraction 193 

Tubular Fields 194 

Reversal of Color Fields 195 

Dyschromatopsia. Color Amblyopia 196 

Neurasthenia 196 

Spiral Field of von Reuss 197 

Wilbrand's Exhaustion Field 198 

Forster's Method 198 

Oscillating Fields 199 

Migraine and Scintillating Scotomata 200 



APPENDIX. 

Field of Monocular Fixation 207 

Degree of Strabismus 208 

Determining the Presence of Diplopia 209 

Location of Foreign Bodies 209 

Bibliography 211 

Index • 225 



PART I. 

INTRODUCTORY. 

Definition. — By perimetry is meant a study of 
central and of indirect vision, or that part of the field 
from which the eye at rest can receive impressions. 
By the use of the ophthalmoscope the observer has 
the means of examining and studying directly and 
indirectly changes which may take place in the media, 
the retina, choroid and sclera. Some of these changes 
are macroscopic, and therefore open to direct inspec- 
tion, while others are microscopic or so minute as to 
escape observation by the use of the ophthalmoscope. 
It is in this latter group of cases that a study of the 
projected field of vision as determined by the practice 
of perimetry is of particular value. On the other hand, 
gross fundus and media changes observed by the 
ophthalmoscope are confirmed and amplified by ob- 
jective perimetry. In a study of diseases of the optic 
nerve, however, only gross changes, such as marked 
atrophy, may be observed by the ophthalmoscope, 
and as atrophy does not manifest itself in the nerve 
head when the visual tract is diseased above the primary 
optic centers, the ophthalmoscope cannot aid us in a 
study of such conditions. In fact its usefulness in 
optic nerve disease has its limitations. 

It may be said, therefore, of perimetry that it is a 
valuable aid in the diagnosis of intra-ocular diseases 
and it is the sine qua non in the diagnosis of disease of 
the visual tracts posterior to the eyeball. 

Central and Indirect Vision. — Vision is of a 

twofold character: (i) central, or that part which 
2 



18 INTRODUCTORY 

allows the eye to fix intently on a small object, and, 
(2) indirect or eccentric vision. When one fixes 
central or macular vision upon an object, it is possible 
at the same time to note with considerable detail 
objects situated remotely from the point of fixation. 
This is indirect vision. The fovea in the macular 
region is regarded as the center of vision because 
of its great sensitiveness to clear perception. Visual 
acuity here reaches its greatest development, and it 
recedes rapidly in the area immediately surrounding 
the macula and less rapidly beyond until the periphery 
of the retina is reached. Central vision notes details 
of objects at rest, but moving objects are observed 
with more accuracy by indirect vision. Similarly, 
although central vision is sharpest in good light, in 
peripheral parts of the retina, adaptation, or the ability 
of the eye to adjust itself to varying degrees of light, 
is more highly developed. It is therefore necessary 
to study both central and indirect vision in the normal 
individual in order to have a standard with which to 
compare pathologic or diseased conditions. Perimetry 
is especially concerned in a study of the projected 
indirect field, although the macula and adjoining areas 
must also be studied carefully when central visual 
acuity has become impaired. 

Visual Acuity. — The term visual acuity is especially 
applied to direct or central vision, although it is a 
relative term and also a function of indirect vision. 
By this term is meant either the ability of the eye to 
recognize minute points of definite size as separate 
points at a definite distance, or to recognize a point 
of definite size at a definite distance. It has been 
variously estimated that the smallest point distinctly 
recognized by an emmetropic eye subtends an angle 
of one minute. Uhthoff makes it fifty-five and two- 
tenths seconds under the very best light and in good 



INTRODUCTORY 19 

contrast. For perimetric purposes the central visual 
acuity of a given patient is expressed by the usual 
formula, with the Snellen test card as the standard. 
The numerator of the fraction designates the distance 
at which the letters subtend an angle of 5', and the 
denominator, the smallest letters which the patient can 
read at this distance; or to transpose, the numerator 
is the distance at which the test is made, and the de- 
nominator, the distance at which the smallest letters 
read subtend an angle of 5'. This standard is arbitrary, 
but it is generally accepted. Central visual acuity 
therefore is the first fact to be determined in beginning 
a perimetric study. 

The determining of the limitations of the visual 
field of indirect vision is accomplished first by entoptic 
study and second by means of the perimeter. 

Entoptic Study. — Entoptic or subjective study 
of the projected field is made by the patient without 
the aid of instrumentation, and consists in the con- 
centration of the patient upon his projected field before 
a background of uniform color. The noting of moving 
specks before the patient's eyes when caused by 
floating vitreous opacities is an example of simple 
entoptic study. To study the entire field phenomena, 
however, requires training of a high order and rarely 
possessed by an average patient. Perimetric studies 
are therefore of greater and more dependable value than 
entoptic studies alone, inasmuch as the data obtained 
are the combined result of careful observation by the 
physician and to a less extent by the patient. 

Laws of Projection and Direction. — In order to 
understand the relation of points in space to points 
in the retina a study of the laws of projection and 
direction is necessary. 

When a visual impression is made upon the retina 
the image is not observed on the retina itself but is 



20 INTRODUCTORY 

seen in space. 1 A similar phenomenon is observed 
in the sensory nerves of other parts of the body; for 
example, one of the earliest symptoms of hip-joint 
disease is pain on the inside of the knee; the pain of 
pneumonia may be referred to the iliac region of the 
abdomen, etc. The exact point in space to which this 
visual impression is referred and is seen is partly 
determined by the law of direction. A study of Fig. i 
will show that a ray of light from a which passes 
through the nodal point of the lens falls upon the 
retina at a' in the macula. A similar relationship 




Fig. 1. — Diagram illustrating the laws of projection and direction. 

can be established between b in space and V in 
the retina, and c in space and c ! in the retina. The 
laws of projection and direction therefore establish 
the fact that every point in space within the visual 
field has a correlated retinal point. 

Corresponding Retinal Points. — As each point 
in the projected field bears a definite and fixed relation 
to a point in the retina, every point in one retina has a 
corresponding and definitely related point in the other 
retina, and these points are known as corresponding 
retinal points. 

1 See Tscherning's Physiologic Optics, p. 304. 



INTRODUCTORY 



21 



In order to understand the relation of corresponding 
retinal points, the reader is referred to the anatomy 
of the visual tract. The higher visual centers are 
located in the cuneus of each hemisphere. The fibers 
from the right cuneus are collected into a bundle 
known as the right optic tract. In the chiasm the 
tract divides; the uncrossed fibers pass forward to 
the outer half of the right eye, and the crossed fibers 
pass over to the left eye and supply the inner side of 
the left retina. A similar distribution of the left 
cuneal fibers supplies the outer half of the left and 
the inner half of the right eye. This arrangement 
brings homonymous parts of each retina into definite 





3- £ 

Fig. 2. — Diagram illustrating corresponding retinal points. (Hansell and 
Reber.) (Courtesy of P. Blakiston's Son & Co.) 

and fixed relation. An image in space which falls upon 
corresponding retinal points makes an impression 
upon both retinae, but the resulting impressions form 
but a single image. 

What is true of corresponding retinal points is true 
also of larger parts of the retinae, as quadrants and 
halves of the retinae. For example, in Fig. 2 the 
quadrant X' C A' of the left eye corresponds to the 
quadrant X C Am the right eye. A' X' B' half of the 
left retina corresponds to A X B of the right retina, 
etc. The fields are taken separately; therefore in 
disease of the intracerebral portion of the visual tract 
the relation of the corresponding parts is important. 
As will be shown in the study of general pathology of 



22 



INTRODUCTORY 



fields, the dividing line between retinal halves may 
not always be a perpendicular line, but it may be 
oblique. The obliquity, however, will always be the 
same in each eye. 

Factors which Influence the Size and Shape 
of the Normal Field. — In order to outline the extent 
of a field of a given patient and to establish a standard 
for comparison, the perimeter is employed, when the 




180 



165 PUBLISHED BY 165 

BONSCHUR&HOLMES 

PHILADELPHIA. 

Fig. 3. — Normal form fields. 



isQ- 



measurements are made as it were in a hollow hemi- 
sphere, all points examined being equally distant from 
the eye, or the measurements are made on a flat surface 
known as a campimeter. Measurements on these 
instruments have established a " standard visual field" 
which is approximately oval in shape, as shown in 
Fig. 3- 

The extent of the retinal area capable of receiving 
impressions of form and color should determine the 



INTRODUCTORY 23 

size of the projected field. Other factors, however, 
influence the size and the shape of the field to as great 
an extent as the activity of the retina. The position 
of the eye in its bony socket has a direct bearing upon 
not only the size but also the shape of the form field. 
In Fig. 3 the shape and size of the average field for form 
is graphically represented. One notes that the field of 
each eye consists of an irregular oval, the greatest 
extent being toward the temporal region, and the 
narrowest part of the field down and to the nasal side. 
This shape is largely determined by the position of 
the eyeball in its bony socket. 

Bony Prominences of the Face and the Shape of the 
Orbital Cavity. — Temporally there is no obstruction 
to the rays of light falling upon the nasal retina as 
far forward as the convexity of the cornea, the size of 
the pupil, and the physiologic activity of the forward 
part of the retina will permit. To the nasal side the 
field is limited because of the inability of the forward 
part of the temporal retina to receive impressions 
because of the prominence of the nose. The prominence 
of the bony orbit above limits the upper field; the 
lower field is obstructed in a similar manner, but to a 
less extent. 

Activity of the Retina. — The extreme forward part 
of the superior and nasal retina is functionally more 
active because of its almost constant use in our habit 
of looking down and out in orientation, whereas the 
inferior and temporal parts of the retina are less 
constantly used and consequently less sensitive to 
impressions. 

Two factors, therefore, are largely responsible for 
the shape and size of the form fields: (i) the bony 
conformation of the orbital cavity and the face, and 
(2) the greater activity of the superior and nasal 
parts of the retina. 



24 INTRODUCTORY 

Other factors which play a minor role are: 

i. The Width of the Palpebral Fissure. — This will 

determine in some instances the extent of the fields 

altitudinally. 

2. The Size of the Pupil. — A large pupil will allow 
rays to fall farther forward on the retina than a con- 
tracted pupil. The plane of the pupil as influenced 
by the depth of the anterior chamber likewise con- 
tributes. A shallow chamber enlarges and a deep 
chamber tends to contract the field. 

3. Refractive Errors. — Myopia, because of its long 
axis and the greater distance of active peripheral 
parts of the retina from the pupillary plane, tends 
to diminish, whereas, hypermetropia tends to increase 
the field. 

4. Forward Attachment of the Retina. — It is claimed 
(Wilbrand, in N orris and Oliver) that the retina is 
attached farther forward on the nasal side than tem- 
porally. This, however, is not so important a factor 
in the greater extent of the temporal field as the 
absence of obstruction from bony and soft orbital 
tissues. The greater extent of the temporal field is 
due also largely to the greater activity of extreme 
forward parts of the nasal retina. It is constantly in 
use, and therefore more receptive to visual impressions 
than the temporal half. 

5. Intelligence of the Patient. — The degree of the 
intelligence of the patient is important in measuring 
accurately the extent of the field. Taking the fields 
of illiterates rarely does justice to such patients, 
because of slow mental processes and their difficulty 
in understanding just what is required of them. Ordi- 
narily, to obtain accurate results in this latter class of 
cases it is necessary to repeat the measurements 
several times. Each measurement will show slight 
enlargement. This observation is also true to some 



INTRODUCTORY 25 

extent even in the most intelligent, as a better under- 
standing of what is required is obtained after one or 
two examinations. 

6. The Influence of Drugs. — Strychnia is a well- 
known nerve stimulant; it increases reflexes and nerve 
activities throughout the body. In the peripheral 
parts of the retina there is a zone in which rods and 
cones, because of little use, require strong stimulation 
in order to receive definite impressions. Strychnia 
acts as a sensitizer to this zone as well as to all function- 
ating parts of the retina, and therefore increases the 
size of the field temporarily. 

7. Fatigue. — In contrast to the stimulation by 
strychnia is the sedative influence of normal fatigue, 
not the result of neurasthenia. Examination should 
be made when the patient's physical and mental 
conditions are good, and not at the end of a prolonged 
general eye examination. If examined when suffering 
from physical or mental tire the fields obtained will 
show a contraction which is abnormal for that in- 
dividual patient. In functionally abnormal and organic 
processes, this factor is of great importance, as a 
type of field is developed which may be regarded as 
pathognomonic of certain and definite pathologic 
states. 

8. Effect of Light. — The character and intensity of 
light has a direct bearing upon the size of the form and 
color fields, and particularly the latter. In order to 
obtain the maximum form field a good daylight is 
necessary.. This is difficult to secure in the average 
office, and under the most favorable conditions the 
patient's body will cast a shadow which necessarily 
makes the diffusion of light unequal. The newer models 
of the electric perimeters overcome this difficulty but 
have the disadvantage of throwing upon the retina 
light impressions which differ materially from those 



26 INTRODUCTORY 

received by the ordinary white and colored discs 
used in the practice of perimetry. For practical 
purposes, therefore, a good daylight, preferably from 
the north, will best serve the purpose with a minimum 
amount of error. The better adaptation for varying 
degrees of light of peripheral parts of the retina over 
that of the macular region has been established, and 
therefore the form field is not influenced in normal 
conditions to any great extent by slight variations of 
light. In pathologic states, however, the intensity 
of light has a direct bearing, and in order to obtain 
uniform results the best possible daylight should be 
used. Although form fields vary little unless the light 
is very much diminished, the behavior of the color 
fields is influenced by even slight differences in the 
intensity of the light. It is probable, too, that the 
variation in the size of the color fields given by different 
observers is due largely to the conditions under which 
the fields are taken. In functional nyctalopia and in 
beginning optic atrophy this tendency for the color 
fields to contract under diminished light is accentuated. 
It is therefore important at all times to measure the 
fields in a good daylight. 

Extent of Normal Form Fields. — In Fig. 4 is 
recorded the average projection of the field for form 
and color. It is a matter of observation that to the 
temporal side white objects may be recognized to 
95 degrees, or 5 degrees beyond the quadrant of the 
circle. This is due to the refractive power of the 
convex cornea and to the great activity of the nasal 
retina, because of being in constant use. Above, 
the form field rarely reaches beyond 44 degrees, to the 
nasal side about 50 degrees, and down it may extend 
to 70 degrees. Beyond these limits a 5 mm. white 
object at rest rarely stimulates the peripheral rods 
and cones sufficiently to form an impression. All 



INTRODUCTORY 



27 



parts of the retina eccentric to the macular region 
possess the faculty of receiving impressions from a 
moving object more readily than from an object at 
rest. In the extreme periphery, therefore, a moving 
object may be recognized beyond the limits referred 
to in the diagram. 

Size of Color Fields. — In an area almost as large as 
that for white, blue may be recognized in good light. 
As noted on Fig. 4, blue extends approximately to 
within 10 or 15 degrees of the form' field. Next in 
order as measured on the perimeter will be seen orange, 




Fig. 4. — Normal color fields taken with a 10 mm. test object. 



red and green. For practical purposes, yellow, which 
is larger than blue, and orange are rarely measured — 
blue, red and green being sufficient for clinical work. 
Red occupies an intermediate position between blue 
and green. With a 5 mm. test object, green may be 
regarded as normal if it reaches about 20 degrees 
above and to the nasal side, 25 degrees down and 
30 degrees temporally. The average normal limits 
for red are 40 degrees temporally, 26 degrees up, 
25 degrees in, and 30 degrees down. 

A 5 mm. test object should be taken as a standard. 



28 INTRODUCTORY 

With this test object I find the average color fields 
to be as follows: 

Blue. Red. Green. 

Outward 65 40 30 

Upward 39 26 18 

Inward 39 25 19 

Downward 48 30 25 

Hirschberg's measurements of normal color fields 
are: 

Blue. Red. Green. 

Outward 62 52 32 

Upward 40 28 20 

Inward 42 32 20 

Downward 54 47 23 

The table of Hirschberg taken with a 10 mm. test 
object is exceedingly conservative. His figures, how- 
ever, are probably more approximately normal under 
average conditions than those given by de Schweinitz 
for the same sized test object, de Schweinitz gives 
the following approximate physiologic limits of the 
blue, red and green fields when taken with a 10 mm. 
object. 

Blue. Red. Green. 

Outward 80 65 50 

Upward 40 33 27 

Inward 45 30 25 

Downward 58 45 30 

These figures may be accepted as approximately 
normal for the average individual under the most 
favorable conditions. Practically, however, one will 
rarely find these results even in normal individuals. 
Five and even 10 degrees less are more frequently 
obtained in normal vision, because the ideal condi- 
tions necessary for perimetry are rarely obtained in 
the average room. As Wilbrand has pointed out, 
all colors as they pass from the extreme periphery 
toward the center give sensations of being mixed with 
black and white, and therefore appear in varying 
shades before full saturation takes place and the color 



INTRODUCTORY ' 29 

is recognized by the patient. This point of recogni- 
tion will vary with the individual, and especially is 
influenced by sex. It is a well-known fact that women 
can recognize colors better than men, and have larger 
color fields. It is evident, therefore, that one cannot 
be arbitrary in the exact size of normal color fields. 

Color Vision Present Throughout Form Field. 
— The limitation of the color field as indicated in the 
diagram does not mean that the peripheral retina is 
totally blind to these colors. If the examining object 
is increased to a sufficient size, color perception may 
be noted in the periphery almost to the extent of 
form. However, to determine the relative sensitive- 
ness of the retina to form and color stimulation, an 
object of uniform size is used. A disc 10 mm. in 
diameter, or preferably 5 mm., is employed; and the 
field recorded in Fig. 4 represents the approximately 
normal limits when examined with a 10 mm. disc on 
an arc perimeter of a 13-inch radius. 

Mariotte's Blind Spot. — The optic nerve enters 
the eyeball about 15 degrees to the inner side of the 
macula or point of central fixation, and a little above 
the horizontal. In the nerve head, or papilla, the 
visual perceptive organs, the rods and cones, are not 
in evidence. This area is therefore blind to all forms 
of visual impressions, and it gives rise to a blind spot 
or scotoma in the visual field, known as the blind 
spot of Mariotte. In the charted field, therefore, 
it is about 15 degrees to the outer side and a little 
below the center of fixation. 

Van der Hoeve 1 found in the examination of one 
hundred young adults a blind spot which averaged 
7 degrees vertically and 5 degrees in horizontal diameter. 
He, with Haycroft and others, also found an area 
surrounding the blind spot in which color perception 

1 Arch. f. Augenh., lxx, 158. 



30 



INTRODUCTORY 



was not possible. My own studies confirm these 
observations as to the size of the blind spot. The 
average normal blind spot is 13% degrees from central 
fixation, 5 degrees in width and 7 degrees in length, 
and extends 2 degrees above the horizontal and 5 
degrees below the horizontal meridian. 1 It varies 
more frequently in normal limits in the vertical diameter 
than in the horizontal. In numerous cases examined 
and in a study of my own blind spot I have found 




Fig. 



-160 180 160' 

V. 

5. — Binocular fields. (From Wilbrand and Saenger, after Forster. 



that color limits as well as form limits are sharply 
defined in good daylight. I am therefore inclined to 
regard an indistinct scotomatous area around the 
blind spot as indicative of the beginning of abnormal 
qualitative color change rather than a physiologic 
condition. 

Normal Binocular Fields. — The normal field 
thus far described is that of a single eye. In the lower 

1 Exact measurements are 7° 40' in vertical axis, and 5° 28' in horizontal. 
Average distance from fixation center is 15° 49'. See Perimetric Studies 
of the Normal and Pathologic Blind Spot of Mariotte, by L. C. Peter, Trans. 
Amer. Acad, of Ophth. and Oto-Laryng., 1915. 



INTRODUCTORY 31 

vertebrates the eyes are placed in the sides of the head, 
and there is no overlapping of the fields of the two 
eyes. As we ascend in the scale of the animal kingdom 
the eyes are placed farther forward in the head, and 
in the higher mammals the fields of vision overlap. 
In man this overlapping reaches its greatest degree. 
Fig. 5 represents a normal binocular field; that is, 
a field taken with both eyes open and fixing on 
the same object. The central clear space DR! out- 
lines the overlapping of the fields for form. RS-D 
represents indirect vision of the left eye alone and .S— 
R f D that of the right eye. Measurements of the binoc- 
ular fields are rarely made. They are not of great 
clinical value aside from the enlargement or contrac- 
tion obtained in divergent and convergent strabismus. 



PART II. 

METHODS OF EXAMINING FIELDS-AUTO- 
PERIMETRY AND PERIMETRY— INSTRU- 
MENTS EMPLOYED-CHARTS. 

AUTOPERIMETRY AND PERIMETRY. 

Entoptic study, or the study of the fields by the 
patient, is a complicated process, and is attended by 
much inaccuracy. It therefore is of little scientific 
value unless the observer is a physician and is conver- 
sant with the subject matter under discussion. Not 
infrequently a patient may see an opacity in the media, 
in the lens or vitreous, and may be able to sketch 
such opacity with a fair degree of accuracy. Techni- 
cally, however, this autostudy of changes in the media 
should not be included in perimetry. I have intelli- 
gent patients who are able to make fairly correct 
drawings and paintings of the scotomata and the play 
of colors which they observe subjectly in scintillating 
scotomata of migraine, and it is not unusual for patients 
to give fairly accurate descriptions of positive scoto- 
mata in chorioretinal disease. The complexity, how- 
ever, of the mental act of fixing with central vision 
and at the same time determining the limitations of 
fields of indirect vision is rarely dependable. Further- 
more, the value of perimetry lies especially in the chart- 
ing of observations made by the various methods of 
examination for preservation and future comparison, 
and nothing short of instruments of precision should 
be employed. 



METHODS OF TAKING FIELDS 



33 



METHODS OF TAKING FIELDS. 

We have three methods and their modifications which 
may be used: (i) the hand method; (2) the campi- 
metric examination; (3) the examination by means of 
the perimeter. 

Hand Method. — In the application of the hand 
method the physician stands directly in front of the 
patient and two-thirds of a meter distant, or at arms* 
length. He covers the patient's right eye, in examining 




Fig. 6. — Hand method of taking fields. 



the left, by his left hand. Closing his left eye he 

fixes his right on the patient's left, requesting the patient 

to look into his open eye. The operator's disengaged 

hand is now moved in gradually from the extreme 

periphery, midway between himself and the patient, 

until the patient is conscious of its presence in his 

indirect field of vision. This is done in various parts 

of the field, and. the results are compared with the 

examiner's own vision. Using his own visual field 

as a standard, any marked cutting or shrinkage in 
3 



34 METHODS OF EXAMINING FIELDS 

the patient's field may be noted. The method can be 
reduced to some degree of refinement for form fields 
if, instead of the hand, a small white object, such as 
the white handle of an ophthalmoscope or a white 
lead-pencil, is substituted for the hand. This is not 
an accurate method, as only gross changes can be 
observed, and is not at all applicable to color fields. 
For approximate results, when marked changes are 
present, it has a wide range of applicability, (i) It is 
a quick method of determining the presence of marked 
contraction, the exact extent of which may be measured 
on the perimeter or campimeter. (2) In hemianopsia 
it is a good method for class demonstration. (3) 
For bedside work and home use, when a perimetric 
examination is not feasible, the hand method may 
be employed. (4) When examining illiterates, feeble- 
minded or people of alien tongue, approximate infor- 
mation may be obtained by this method. (5) A modi- 
fication may be employed in the examination of semi- 
comatose or partly conscious patients if the eye 
reflexes are preserved. In these cases a small electric 
light may be employed, or better still, a cautery which 
can be readily controlled. The electric light diffuses 
its light too freely, whereas the cautery blade is more 
localized. In applying this method one looks for the 
reflex wanking of the lid when the patient becomes 
semiconscious of the brightly lighted cautery in the 
field of vision. It is necessary to observe care in hold- 
ing the lighted cautery a sufficient distance from the 
patient so as not to excite actinic sensibility instead 
of that of light. Unconscious seizures, due to throm- 
bosis, hemorrhage and embolism are common occur- 
rences in adults of fifty years or older; and hemi- 
anopsia is a frequent accompanying symptom in these 
cases, although ofttimes of short duration. In this 
type of case, therefore, this method may be employed 



METHODS OF TAKING FIELDS 



35 



to determine the presence or absence of hemianopsia. 
(6) The light projection of a mature cataract case may 
also be taken in a dark room, in a similar manner, 
by using a small electric light, such as is employed 
in the various types of luminous ophthalmoscopes. 
More accurate work may be done by suitable modifi- 
cation on the campimeter, or in the absence of the 
latter, a fair degree of knowledge of the patient's light 
projection can be obtained in this manner. (7) When 
the fields are cut to any great extent in chronic glaucoma 
and central vision is reduced by corneal haze, this 
same method may be applied to roughly determine 
the amount of shrinkage in the fields. 

While a helpful method in routine examination of 
a patient, especially when pressed for time, as in 
hospital work, the author wishes to emphasize the fact 
that this hand method is only approximately correct, 
and should be followed by one or both of the more 
accurate methods about to be described. 



+ _ 



Fig. 7. — A form of chart for recording campimetric fields. 



Campimetric Method. 1 — The blackboard, or cam- 
pimeter, is a much-neglected aid in the diagnosis of 
defects in the visual field. It consists of a blackboard 

1 Introduced by von^Graefe. 



36 



METHODS OF EXAMINING FIELDS 



4 feet long and 3 feet wide, which may be marked either 
in squares of 3 inches each, as in Fig. 7, or in circles, 
as in Figs. 8 and 1 1. 



4! 


i° 








c 


>° 








4J 




7\ 






4 


0° 






%> 




__3 


q^_ 










1 


0° 
0° 
















\5 











c*n° 


4 


0° 


30° 


2 \°r\ r 


> /\ 




Vo 2 ' 


0° 


30° 40 


W 








\0{ 






)01 
















\J_ 


o> 
















^ 2 


0!^ 
















, 3 


ol- 
















4 


0° 























90 e 



135° 180° 135° 

Fig. 8. — Campimetric chart used for recording fields taken on the author's 

hand campimeter. 



In the former a special chart must be prepared for 
recording fields; whereas if the latter be adopted, 
records may be kept on any of the various charts 
now in use. If Fig. 7 is adopted, squares on the black- 
board should be lined with faint white lines 3 inches 
apart. These should be numbered, so as to facilitate 



METHODS OF TAKING FIELDS 



37 



the transfer of the fields obtained on the board to charts 
for purposes of record. In practical work it has been 
found that a board 4 feet long and 3 feet wide, while 
insufficient in size to record the most peripheral 
impressions from the temporal side, for the taking 
of the average pathologic field is quite adequate. 

If the type represented in Fig. 8 is decided upon, 
great care must be observed in drawing the circles. 




Fig. 9. — A diagram showing the relation of a tangent campimeter to an arc 
perimeter. (Weeks.) 



Methods of Drawing Circles on the Blackboard.— 
The proper method of drawing circles on the black- 
board and the determining of their radii may be 
obtained by studying Fig. 9. 

A -B is a line drawn through the center of the board 
and serves as a tangent to the semicircle L-F-O, whose 
radius is 33 cm., or 13 inches. Radii are now drawn 
from the circumference of the circle at 10, 20, 30, 40 
and 50 degrees, and are projected on to the tangent 
A-B. The correct length of each radius for the 10, 
20, 30, 40 and 50 degrees is therefore obtained, 



38 METHODS OF EXAMINING FIELDS 

and by means of a compass the circles may be 
drawn with a fair degree of accuracy. A more 
accurate method of determining the radius of each 
circle is the following: Multiply the natural tangent 
of each angle desired by the radius of the arc L-F-0 
(Fig. 9) or the distance from the patient's eye to the 
center of the board, which ordinarily is 33 cm., or 13 
inches. The natural tangent of a given angle may 
be obtained by referring to any trigonometry. For 
the convenience of the reader the following table of 
natural tangents for the angles will be found necessary 
in making up a campimeter. 



ingles. 


Natural tangents. 


Angles. 


Natural tangents. 


5° 


0.0875 


50° 


1.1918 


10° 


0.1763 


60° 


1.7321 


20° 


0.3640 


70° 


2.7475 


30° 


0.5774 


80° 


5.6713 


40° 


0.8391 


90° 


Infinity 



Example. — The radius of the 5-degree angle is 
desired for a 13-inch distance. Multiply 0.0875 by 
13 inches and the length of the radius of a 5-degree 
angle will be 1.1375 inches. The radii of the other 
angles may be obtained in the same manner, either 
in terms of inches or in centimeters if the metric 
system is used. 

In many instances it will be best to study the field 
at a greater distance than 13 inches. A second cam- 
pimeter therefore should be provided, with circles 
drawn for the distance desired. If the examination 
is to be made at 1 meter, instead of our multiplier 
of 13 inches, 1 meter, or 39 inches, should be sub- 
stituted. 

Referring to Fig. 9, one can observe at a glance why 
these circles should be farther apart as the periphery 
is approached. The degrees in an arc of a circle are 
placed at equal distances, but when these radii are 



METHODS OF TAKING FIELDS 



39 




projected on to the tangent of the circle which repre- 
sents the blackboard, the distance from the perpen- 
dicular increases as the degrees on the 
circle increase. In fact, this furnishes 
the principal objection to the use of 
the campimeter for scientific work. 

When examining the fields with a 
campimeter a special test object is 
necessary. It consists of a black disc 
attached to a black handle about 15 
inches long. In the center of the black 
oblong, as in Fig. 10, is a small white 
disc, 5 mm. in diameter, which is used 
as a test object for form. By means 
of the catch (at E) the white disc can 
be replaced by blue, red or green, so 
as to check inaccuracies and inattention 
on the part of the patient. Modifica- 
tions of this test object can be made 
to satisfy the fancy and convenience 
of the operator. The essential require- 
ments are: (1) the test object shall be 
definite in size, 5, 10, 15 and 20 mm.; 
(2) the disc shall be round and not 
square, as a square disc contains a 
larger area than a round disc of equal 
diameter; (3) the colors must be stand- 
ard and uniform colors. This latter 
condition is one of the most important 
precautions in the practice of per- 
imetry. For example, if the red con- 
tains too much orange tint the 
fields will be wider than they should 
be. The same may be said of green 
and of blue. For this reason Wilbrand test object for peri- 
suggests the use of Heidelberg flower metric study on cam " 

pimeter or arc per- 
paper. imeter. 



Fig. 10.— Author's 



40 METHODS OF EXAMINING FIELDS 

The author's 1 hand test object is well adapted for 
use on the blackboard or perimeter. In addition to 
the three colors and white being arranged on one slide 
the size of the test object can be controlled by rotating 
before it a diaphragm containing openings which vary 
from I mm. to 10 mm. in diameter. The compactness 
of this test object compensates for its apparent clum- 




Fig. 11. — Campimeter drawn in circles. 

siness. It saves the annoyance of carrying a large 
number of test objects necessary to make suitable 
examinations. The instrument may also be used to 
advantage on a non-registering perimeter. 

Practical Use of Campimeter. — Instead of a black- 
board 4 feet by 3 feet, blackboard cloth of the same 
dimensions or larger may be used. The latter may 

1 See Archives of Ophthalmology, June, 1915. 



METHODS OF TAKING FIELDS 41 

be attached to a roller and when not in use may be 
rolled up. This will take up less space, but will be 
found a little less convenient in making examinations, 
unless the room is well lighted, as it must be supported 
against the wall. If the campimeter board is used, 
it may be placed on an easel or, better still, on a port- 
able sliding rod support. It must be placed in a good 
light, preferably between two windows of northern 
exposure. The patient is seated before the board, on 
a stool which can be raised and lowered if the board 
cannot be readily raised and lowered, because it is 
essential that the eye under examination shall be 
exactly on the level of the center or fixation object of 
the campimeter. The disengaged eye is blindfolded 
carefully so as to exclude light, and the patient is so 
placed that the eye under examination shall be directly 
in front of the fixation object, at a distance of 33 cm., 
or 13 inches, from the central point. It is essential 
that this radius of 33 cm. shall be carefully maintained 
throughout the examination, as the campimeter is 
drawn with a radius of one-third of a meter as a basis. 
The patient fixes upon the object in the center of 
the board, and the test object is slowly moved from 
the periphery toward the center. He is told to signify 
in some manner when the disk first makes its appear- 
ance in his visual field, and a check mark is placed 
upon the board at this point. When examined for 
the first time, answers are usually inaccurate, as taking 
of fields is a matter of training, not only in an illiterate 
patient, but also in the more intelligent. The patient 
must be made to understand fully what is expected 
of him. Many years ago Ole Bull pointed out the 
fact that if a patient is first drilled in mapping out 
Mariotte's blind spot the estimation of the form and 
color fields will be much more easily and accurately 
obtained. My own experience confirms this observation. 



42 METHODS OF EXAMINING FIELDS 

It is a well-known fact that moving objects are observed 
in the extreme periphery more quickly than a fixed 
point or color can be detected. It is advisable, there- 
fore, to make these examinations very slowly and with 
deliberation. The value of the shutter on the test 
object handle will be appreciated, because by changing 
the white disk to one of the colors one can note whether 
the patient's answers are correct or doubtful. These 
measurements are made throughout the circumfer- 
ence, and the results are transferable to a suitable chart. 

Lohmann 1 observes that fields taken by passing 
the test object toward the center are larger than when 
the object is passed from the center to the periphery. 
Frequently, however, in actual practice, the reverse 
will be found. 

The number of points to be examined in determining 
the form field must necessarily depend upon the char- 
acter of the changes found. If the field is approxi- 
mately normal, or there is a fairly regular concentric 
contraction, about eight points of the circumference 
will suffice. When, however, there chances to be an 
unequal contraction and angular defects are present, 
it is necessary to continue the examination until the 
defect is properly outlined. 

Color Examination. — It is immaterial in what order 
the patient is examined for color defects. It is, however, 
a good plan at all times to proceed in an orderly manner, 
and the blue, red and green fields are examined in the 
order mentioned and in the manner described for form, 
with these important differences: (i) Red, for example, 
may look pink to the patient when it is first observed 
in his field of vision, and he must be instructed not to 
call the color until he recognizes it as a distinctly red 
object. Thorough saturation is necessary. The same 
applies to blue and green. Inattention to this point 

1 Disturbances of the Visual Functions. 



METHODS OF TAKING FIELDS 43 

may cause inaccurate results. (2) The average patient 
does not know that the red and green fields are much 
narrower than form and blue fields, and very fre- 
quently there is a tendency on the part of the patient 
to answer too soon or glance from the fixation-point to 
the test object, and thereby cause inaccurate results. 
(3) Before undertaking the examination of the color 
fields it is necessary for the operator to satisfy himself 
that the patient is not color-blind to one or more of 
the colors used in the test. 

After carefully recording the results of the examina- 
tion on a chart, for purposes of record, the fellow- 
eye is examined at the same sitting, and as nearly 
as possible under the same conditions. 

Examination for Scotoma. — It is a part of the ex- 
amination, after completing the outlines of the fields, 
to test all parts of the field for form and color defects 
or blind spots known as scotomata. 

The campimeter is ideally adapted to the careful 
outlining of scotomata. If the area to be examined 
is within the 30-degree circle the smallest test object 
which the patient can recognize within this radius 
is used. Bjerrum recommends very minute objects 
for this test. By means of these small objects, a blind 
area is defined with greater accuracy than when the 
5 mm. or 10 mm. objects are employed. Great care 
and patience are necessary to properly outline small 
scotomata. In the blind area the same color test 
should be. made as in defining the extent of the field 
peripherally. In this test the color ceases to be recog- 
nized, although a zone of qualitative color change 
should be sought. For example, beyond the blind area 
for green there may be a zone in which the green object 
is seen as white and gradually takes on its color value as 
the test object approaches normal retina and choroid. 
This indistinct zone should receive as much care 



44 METHODS OF EXAMINING FIELDS 

as the area of relative or absolute blindness. In the 
earliest stages of the development of a scotoma an 
indistinct scotoma may be mapped out before a relative 
or absolute blind spot makes its appearance. In 
searching the field, therefore, for color defects, it is 
quite as important to determine qualitative changes 
in color in certain areas as quantitative. 

To outline Mariotte's blind spot a test object 
2 mm. in diameter is most satisfactory, providing the 
patient can recognize this object within the 20-degree 
circle. If the operator experiences difficulty in deter- 
mining the presence of a blind area the patient's 
distance from the board can be increased to one meter, 
when the scotoma will be found to be increased in 
size proportionately and may be readily outlined. 

In the mapping of scotomata, Bjerrum's method, 
or modifications of the same, are largely practised. 
He recommends the use of small test objects, 1 mm. and 
2 mm. in diameter, instead of the 5 mm. and 10 mm. 
disks usually employed. The test objects consist of 
ivory balls varying from 1 mm. to 10 mm. in diameter, 
attached to a small black rod. The examination is 
preferably made on a large black screen, and the 
examination is begun at the usual distance of 33 cm. 
with a 10 mm. object. It is further amplified by an 
examination at 2 meters and with a smaller test 
object. As the blind spot increases in size as the patient 
recedes from the screen the outline of a scotoma may 
be readily determined. Bjerrum claims, and justly so, 
that a disc 10 mm. in diameter will stimulate a great 
many more retinal elements than a smaller object, 
and that therefore by using the larger disc, blind areas 
may be overlooked, especially when of very small 
size. By this method, also, he claims the outline of the 
blind area is more carefully defined. Traquair 1 has 

1 Ophthalmic Review, March, 1914. 



METHODS OF TAKING FIELDS 45 

recently emphasized the value of Bjerrum's method, 
and urges the practise of what he calls the quantitative 
test for form and color. Following Bjerrum's method 
of outlining a scotoma, he recommends the use of a 
very small test object to ascertain whether areas which 
were sensitive to impressions when the larger test 
objects were used fail to respond to smaller objects. To 
accomplish this reduction in size, either the examina- 
tion can be made at the usual distance with a very 
minute test object or the patient's distance from the 
board can be increased to I or 2 meters. Bjerrum 
recommends the latter method. In making an 
examination at I or 2 meters one should not lose 
sight of the fact that the opportunity for error is 
proportionately greater. It is more difficult to keep 
the patient's eye fixed, and color values are uncertain 
at so great a distance when the object is so small. 

It has been my practice to reverse the order of the 
examination. When a scotomatous area has been 
detected by the coarser methods on the ordinary 
campimeter at 33 cm., I make a final and analytic 
study of the same case at closer range on my hand 
campimeter, i. e., at a 16.5 cm. distance. At this 
close range there are fewer opportunities for error 
and the color values are more dependable. In fact, a 
patient of average intelligence will usually volunteer 
the information that in certain areas, red becomes 
pink or even white, blue is a slate color or black, 
and green is pale or even white. Alterations in the 
quality of the color are quite as significant as the 
quantitative test suggested by Traquair, Bjerrum, 
Berry and others. 

Traquair has especially emphasized in his paper the 
importance of most painstaking examination of scoto- 
matous areas by the refining methods which we have 
at our command. The warning of Traquair is espe- 



46 METHODS OF EXAMINING FIELDS 

cially applicable to central field defects. The cruder 
methods employed routinely in practice are not 
sufficient to bring out all that can be learned from a 
careful study. 

Scotomata in Imperfect Fixation. — When central 
fixation is much reduced or is included in the scoto- 
matous area, special methods can be practised in order 
to map out such defects. Most of the methods sug- 
gested are based on the principle of binocular fixation, 
or rather fixation with the uneffected eye. This method 
presupposes, without guarantee of its correctness, that 
there is a normal muscle balance, a condition which 
is most unlikely, excepting possibly in very recent cases. 
Von Szily used a funnel-shaped tube, through which 
the uneffected eye was fixed. Walker, of Boston, a year 
or two ago, had a similar device. Schlosser covers one 
eye, for example, with a red glass in making an examina- 
tion for green, or vice versa. Tomlinson's scotoma- 
graph with stereoscopic fixation, and Hoetz's stereo- 
scopic cards also require fixation with the healthy eye, 
and therefore again are of doubtful value. 

Reber has suggested a four-point test which may be 
used to advantage in intelligent patients. He roughly 
maps out the blind area as shown in Fig. 12. The 
crossed lines are then erased gradually until the patient 
is conscious only of the ends of the lines, as at A, 
B, C, D, in the figure. Fixing these points, the exami- 
nation is continued until the blind area is carefully 
charted. This method necessitates the concentration 
of the patient on at least five points at the same time, 
and consequently, like entoptic studies, can only be 
used in selected cases. In these cases, however, it is 
an accurate method. 

Hess's method consists in studding the central field 
of the perimeter or scotometer with small electric 
lights arranged at definite and regular intervals. These 



METHODS OF TAKING FIELDS 



47 



lights are turned off and on alternately, and the blind 
area is charted by noting which lights are visible and 
which fail to cause retinal impressions. 

The most practical method, and the one which 
probably is freer from error than any of those men- 
tioned is the following one: The patient is placed 
before a perimeter or campimeter as usual with one 
eye bandaged. His index-finger is placed on the fixa- 




FiG. 12. — Diagram illustrating Dr. Reber's four-point method of fixation in 
mapping out a central scotoma. 



tion-point and he is instructed to look at the end 
of his finger. Providing the person's muscle sense is 
normal, this method is applicable to nearly all cases. 
In locomotor ataxia, it might not be applicable. If 
this latter method cannot be employed, the covered 
eye may be frequently uncovered to preserve central 
fixation, if the covered eye has fairly normal vision and 
the muscle balance is not much disturbed. 



48 METHODS OF EXAMINING FIELDS 

Advantages and Disadvantages in the Use of the 
Campimeter. — There are so many commendable features 
about the campimeter that its defects are thereby 
offset, and the author feels that it is a valuable aid 
to the study of fundus conditions and a necessary 
part of the office equipment. 

Disadvantages. — One needs but glance at Fig. 9 to 
note the great objection to this instrument. As the 
periphery is approached, the distance from the eye 
to the blackboard rapidly increases; furthermore, the 
test object grows smaller in the direction in which 
the field is examined, because the object is observed 
at an increasingly obtuse angle and from a greater 
distance. These two facts furnish the chief and more 
serious objections. Second, it is impossible to record 
extremely peripheral impressions, especially in the 
temporal side, on a flat surface. Third, it is a rather 
cumbersome piece of furniture, and occupies consider- 
able space. Fourth, automatic recording devices cannot 
be adjusted to it in order to facilitate an examination. 
Fifth, it is difficult to guard against shifting of the 
patient's sight, as no chin rest is provided, and another 
source of inaccuracy is added to the results. 

Advantages. — For the defining of scotomata, or 
blind spots, it has an elasticity which the perimeter 
does not possess. (See Author's Hand Campimeter.) 
If there is any doubt as to the presence of a small 
scotoma, the patient's distance from the board can be 
increased until the blind area has increased to a well- 
defined size. Second, for defining and recording light 
projection in a cataractous eye, it is admirable. Third, 
for establishing the presence or absence of the tubular 
field, as found in hysteria, it is much superior to the 
perimeter. Fourth, it is less complicated and therefore 
better adapted to the examination of an illiterate 
patient. Fifth, the cost is so nominal (a matter of 



METHODS OF TAKING FIELDS 49 

four or five dollars) as to make it possible for any 
oculist to possess it. Sixth, if the blackboard cloth is 
used, it is so readily handled that it can be taken to a 
patient's house if necessary, with little inconvenience. 

Some of the disadvantages of the campimeter become 
of secondary moment in actual practice. For example, 
while it is true a space of four feet by three feet furnishes 
an insufficient area upon which to chart all fields, if 
the campimeter is reserved for cases which have con- 
siderable defect, approximately correct records for such 
patients may be obtained; and instead of holding 
the test object flat upon the board in the peripheral 
field, it can be held at an angle so as it bring its entire 
surface into view, or a round test object may be used, 
thereby reducing this source of inaccuracy to a mini- 
mum. In actual practice, therefore, the author has 
come to regard the campimeter as a most valuable 
part of his office equipment. 

Measuring of Light Projection. — The instrument is 
so admirably adapted to the study of light projection 
in mature cataract that mention of it at this point 
will not be amiss. The central fixation object and 
test object may be small electric lights of ground glass, 
or if these are not available, tallow candles will suffice. 
By this method a light field can be taken and recorded 
in a scientific manner, and a more accurate knowledge 
of fundus and optic nerve conditions may be established 
than in the usual method of taking light projection. 

Author's Hand Campimeter . — I have found the cam- 
pimeter so practical, and on the whole so much more 
satisfactory than the perimeter, that I have devised 
a hand campimeter which may also be called a sco- 
tometer. It is extremely well adapted to the study of 
early changes in the color fields and early evidence 
of disease in the central zone. 1 

1 See Ophthalmic Record, July, 1915. 



50 METHODS OF EXAMINING FIELDS 

The face of the board fourteen inches square is 
marked as in Fig. 13 and is a half reduction of the 
ordinary campimeter or tangent blackboard. It is to 
be used at six and a half inches, or approximately 
one-sixth of a meter. To the bottom of the board is 
attached a quadrant of black metal, the upper end of 




Fig. 13. — Author's hand campimeter. 

which is shaped to fit against the cheek and is in line 
with the center and exactly six and a half inches from 
the board. The entire instrument is supported by a 
handle, and it is so light in weight that the patient 
can hold the board in place before the eye during the 
examination. 



METHODS OF TAKING FIELDS 



51 



To either side of the center are drawn the average 
size normal blind spots, which are found to be 5 degrees 
broad and 7 degrees in length. 

The test objects are 5 mm. and 2 mm. in diameter, 
and are readily attached to a black handle which is 
made so small in diameter as to be inconspicuous. For 
testing color fields of areas beyond 20 degrees the 5 mm. 




Fig. 14. — Author's hand campimeter in use. 

test object is used, and within the 20-degree circle a 
2 mm. object is found to be most serviceable. 
The advantages of this campimeter are: 

1. Its portability and lightness. Because of its size, 
the patient can be examined before a window in the 
very best daylight. 

2. The range of six and a half inches admits of 
greater accuracy, because the test object is seen with 



52 METHODS OF EXAMINING FIELDS 

greater definiteness, and scotomata are more sharply 
outlined. Furthermore, I have been able to outline 
more accurately and satisfactorily indictinct scotoma- 
tous areas beyond the relative or absolute scotomata. 

3. The measurements of the normal or abnormal 
blind spot are more accurately made than by any 
other method which I have employed, and abnormalities 
in the size of Mariotte's blind spot are readily detected 
by immediate comparison with the average blind spot. 

4. The study of the color fields is made with greater 
accuracy than when the patient is the usual distance 
from the board or the perimeter. 

5. The uniform distance of six and a half inches 
from the board is always maintained, and the small 
fixation object insures less wandering and therefore 
greater accuracy. 

6. Like the large blackboard, the scotometer is 
more flexible than an arc perimeter or scotometer, 
and is therefore ideally adapted to the study of the 
central part of the field. 

The most serious objection to this board, as well 
as to the larger campimeter, is the apparent inaccuracy 
of the results beyond the 40th degree. In this cam- 
pimeter, however, this objection is reduced to a minimum, 
because its range is not much beyond the 40th degree, 
and such inaccuracies as may occur around or within 
the 40th degree may be regarded as negligible quanti- 
ties. Within these boundaries I know of no perimeter 
which admits of such accuracy in definition as this 
hand campimeter. 

Tangent Curtain of Duane. — In Fig. 15 is represented 
the tangent curtain of Duane, a description of which 
has recently appeared in the Archives of Ophthal- 
mology, 1914, vol. xliii, No. 6. The curtain is black 
on the examining side and white on the back, upon 
which are charted the lines as represented in Fig. 15. 



METHODS OF TAKING FIELDS 



53 



The examination is conducted as on any campimeter. 
Instead, however, of using the chalk to record results, 
a pin is thrust through the curtain and the readings 
are taken from the back of the instrument. In Figs. 



H— 


--^--^-^i 


s X 3 


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Fig. 15. — Tangent curtain of Duane. (Courtesy of G. P. Putnam's Sons.) 

1 6 and 17 he has devised special charts for preservation 
of records when the examination is made at 30 inches 
and for readings at 60 inches. The author claims 
special adaptability to the study of (1) central and 



54 



METHODS OF EXAMINING FIELDS 



£Z JL Zr- S*Z ZV "/X-/^ ^ K r- \ ^ 


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Fig. 17 
Figs. 16 and 17. — Duane's tangent curtain charts. (Courtesy of G. P. 

Putnam's Sons.) 



METHODS OF TAKING FIELDS 



55 



pericentral scotomata and enlargements of the normal 
blind spot; (2) to delimit the field of vision; (3) to 
plot the field of fixation; (4) to plot diplopia and the 
field of double vision. 

The Perimeter. — The methods thus far described 
have the objection that the distance of the fixation 
object from the eye varies as one recedes from the 
center to the periphery of the field. Examination 
should be made if possible in a hollow sphere so as to 
subject all parts of the retina to like conditions. The 
perimeter, therefore, as devised by Forster, and copied 




Fig. 18. — Forster's perimeter. (Norris and Oliver. Courtesy of 
J. B. Lippincott Co.) 

in all essentials by other ophthalmologists, meets this 
condition. It consists of an arc of a circle 180 degrees 
(b, b), supported by the arm a, and made to revolve 
about the pivot at r. The semicircle is made with a 
radius of 33 cm., or 13 inches. On the outside of the 
semicircle b, b are recorded the degrees so as to admit 
of a ready reading. The surface of the plate m is 
divided into meridians. It moves with the semicircle 
and the meridian along which the measurement is made 
can be read off from the surface m. A chin rest is 
provided for support (d) at a point 33 cm., or 13 inches, 
from the center of the arc b, b. This chin rest can 



56 METHODS OF EXAMINING FIELDS 

be raised or lowered so as to bring the eye under 
examination over the point/. The point/ is stationary, 
and is on the same level as the fixation-point on the 
arc. The perimeter is supported on a table which can 
be raised or lowered to suit the patient's height. The 
same result can be obtained by a stool which can be 
raised and lowered. It always is important to have 
the patient seated comfortably, and not in a cramped 
position, for the latter not only adds to the fatigue 
of the examination, but distracts the patient's attention, 
which must be concentrated on the work at hand. 

The examination on this type of perimeter proceeds 
in the same manner as in the examination on the 
campimeter, the test object being moved quietly along 
the inside of the arc b, b in the various meridians, 
and the results are recorded on a suitable chart. 

Self -registering Perimeter. — In the more modern 
perimeter, a self-registering device is attached at the 
point m, and the examination is made more readily 
and recorded fairly accurately. In this type of instru- 
ment, a slide carrying the test object is placed on a 
quadrant of a circle, as b, b. It is carried by a system of 
cords and pulleys, and is attached to the self-registering 
device, and the technic of the examination is thereby 
much simplified. To the back of the arc is attached, 
at the point of fixation, a large black disc to furnish 
a restful background for the macula and adjoining 
areas. This is an important feature of the perimeter, 
and in this respect the campimeter is even more satis- 
factory because of the total absence of colors or bright 
objects which might divert the patient's attention. 

One of the objectionable features of the perimeter 
is the noise which the carriage makes as it is passed 
back and forth. It apprises the patient of its presence 
by this noise, and because of its size, if moved too 
rapidly, the movement is mistaken for the visual 



METHODS OF TAKING FIELDS 



57 




Fig. 19. — McHardy's self-registering perimeter. 




Fig. 20. — Universal perimeter. 



58 METHODS OF EXAMINING FIELDS 

impression of the small white disc, which is not yet 
in evidence. Instruction, however, to the patient to 
ignore these facts usually suffices to overcome this 
source of error. 

The entire instrument is painted black so as to be 
unobtrusive to the patient's eye, and that the fixation 
and test object may show well in contrast. If an arc 
perimeter is used, it is well to have at hand a three- 
winged black or neutral gray screen to place two or 
three feet back of the perimeter, so as to shut off all 
projection of images from the objects in the room. 
The screen should be at least six feet high. The fixation 
object should be white and 5 mm. in diameter. If 
too small, it will require too much effort to constantly 
fix the fovea upon it, and if too large, it will allow 
central vision to wander perceptibly. The test object, 
as in use on the campimeter, should be 5 mm. or 
10 mm. in diameter, providing the patient's vision is 
not too much reduced. If sight is much damaged, the 
smallest disc which the patient can see a short distance 
eccentric to the fixation-point may be employed. In 
actual practice we use a 5, 10, 15 or 20 mm. disc, 
and the size used is designated upon the chart upon 
which the fields are recorded. These remarks apply 
to the campimeter as well as the perimeter. In defining 
a blind spot, or scotoma, however, a smaller test object 
should be used, a 1, 2, or 3 mm. disc if it can be clearly 
seen in a healthy part of the retina. By reducing the 
size of the test object, a cleaner cut outline of blind 
areas may be obtained, and small blind spots may be 
discovered which would escape detection by use of the 
larger disc. The small-sized test objects will also be 
found useful in sharply defining types of hemianopsia, 
or half-vision. 

Reber's Umbrella Perimeter. — Drs. Reber and McCool 
have endeavored to combine the advantages of the 



METHODS OF TAKING FIELDS 



59 



perimeter and campimeter in the form of an umbrella 
blackboard. A similar device has been used recently 
by Walker in his study of the Wernicke pupillary 
phenomenon. The disadvantage of this form of per- 
imeter is the inability to light up the interior of the 
hollow sphere by good daylight. If daylight could be 




Fig. 21. — Schweigger's perimeter. 



evenly diffused over the interior surface, the instru- 
ment should yield accurate perimetric measurements. 
Bedside and Hand Perimeters. — Bedside work requires 
a perimeter of special design. Instruments complicated 
and cumbersome have been devised for this purpose. 
None, however, is more practical and at the same time 



60 METHODS OF EXAMINING FIELDS 

so easily used as the hand perimeter shown in Fig. 21, 
known as Schweigger's hand perimeter. 

In this instrument are incorporated all the essential 
elements of a good perimeter, and sufficiently accurate 
work for clinical purposes may be accomplished with it. 
In fact, it is a good portable instrument which may 
also be employed expeditiously in office practice for 
hasty work. One feature of this perimeter deserves 
special mention. Instead of a white fixation object, 
a small mirror is employed, and the patient can watch 
his own eye. It is especially well adapted to the 
examination of children whose attention it is difficult 
to hold. The mirror effect is a novelty which will better 
hold their attention. 

Holth's Chord Perimeter. — S. Holth has recently 
perfected a pocket perimeter especially adapted for 
quick work and so compact in construction that it 
may be carried in the pocket. The arc of the perimeter 
is replaced by two straight wooden rods, representing 
the chords of the two quadrants which would make 
up the arc. The test object is passed along the 
chords, and the author claims results of a fair degree 
of accuracy. 1 

Artificially Lighted Perimeters. — Light is one of the 
essentials in good perimetric work. The field of 
operation should have an even diffusion of good day- 
light. This, as has been said, it is difficult to secure 
in the best-lighted room, because the patient's back 
must be placed to the window so as to light up the field 
of operation. His body will necessarily cast a shadow 
in some parts of the field. In order to obviate this 
difficulty, enterprising firms have placed on the market 
several types of instruments, beautiful in design and 
workmanship, but defective in practical work: (1) 
because they are, as a rule, complicated and therefore 

1 Ophthalmoscope, xiii, 14. 



CHARTS AND METHODS OF CHARTING 61 

difficult to keep in good order; (2) because both test 
object and fixation object consist of colored electric 
lights from which the patient receives impressions 
other than those of form and color; and (3) when the 
field is illuminated by artificial light, both form and 
color objects have values which differ materially from 
those which are received in a good daylight. For 
practical use, therefore, a self-registering perimeter, 
illuminated by good daylight, is the instrument to be 
recommended, as with it errors and inaccuracies are 
reduced to a minimum. 

Scotometer. — An instrument especially devised for 
defining defects or blind spots in the macula and its 
immediate surroundings is Bardsley's scotometer. The 
particular advantages of this instrument are: (1) the 
field under observation has a solid background of 
black, which is an ideal condition for mapping out fine 
defects; and (2) the instrument is operated quietly, 
and blind areas may be discovered with a maximum 
degree of accuracy. Its greatest objection is the same 
which may be applied to any form of arc perimeter, 
namely, inelasticity. 

Priestley Smith's scotometer has been found satis- 
factory by some ophthalmologists. It consists of a 
black disk 39 cm. in diameter, and the examination is 
made at a distance of 35 cm. Like the Bardsley 
scotometer and the arc perimeter, it is totally lacking 
in elasticity, which is the essential element in mapping 
scotomata. 

The Berry-Haycroft scotometer furnishes a ready 
method of roughly determining the presence of scoto- 
mata. 

CHARTS AND METHODS OF CHARTING. 

The chief value of perimetry lies in the charting of 
results for future study and comparison. These charts 



62 METHODS OF EXAMINING FIELDS 

to be correct should be a miniature of the hollow sphere 
which the perimeter defines in the taking of the field. 
This is impossible, and we must be content with the 
projection of our results onto a flat surface, as in the 
Mercator projections of the earth's surface on maps. 
Our mental habit of seeing things as they should 
be, and not as they seem to us, comes to our rescue, 
and the charts, as now used, are therefore universally 
accepted. When the self -registering perimeter is 
used, the automatic device records accurately the 
findings of the perimeter, providing the chart is 
carefully centered and the automatic device has been 
carefully adjusted. The latter trouble is a frequent 
source of error, and after restringing the instrument 
it should be carefully inspected to make sure the 
recording needle has been properly centered. 

The reader will note that the degree marks on the 
circumference of the charts will vary with each make 
of instrument. It is to be deplored that more uniform- 
ity is not observed in the making of instruments and 
charts to correspond. The author finds the numbers 
as arranged on the McHardy and other modern instru- 
ments more satisfactory, beginning with zero at the 
center of the chart above and ending with 180 degrees 
at the center of the chart below. Fig. 3 is the form of 
chart which the author finds most practical for recording 
purposes, and Fig. 22 for publication purposes. 1 Any 
size of chart which may suit the physician's fancy 
or purposes best may be employed, but uniformity 
in the matter of marking the degrees should be carefully 
observed. For the campimeter, special charts which 
are an exact reproduction of the campimeter should 
be employed, although the regulation chart used on 
the arc perimeter will be found satisfactory. 

For the author's campimeter, the special chart 

1 The latter chart is on cardboard 9 by 14 inches. 



CHARTS AND METHODS OF CHARTING 



63 



should be employed. This chart is an exact reduction 
of the campimeter, and has the advantage of being 
cleanly cut and less covered with unnecessary lines, 
thereby allowing defects in the field to be seen more 
clearly. On this chart is drawn with great care and 
accuracy the size of the normal blind spot, so that the 
slightest increase in its size may be noted (see Fig. 8). 
Recording of Fields Taken on a Non-register- 
ing Perimeter. — The average student finds it difficult 
to transfer the readings from the perimeter to the 
chart. The matter can be simplified by bearing in 




Fig. 22. — Form of chart best adapted for reporting of cases. 



mind that the recording chart is a miniature of the 
perimeter. Hold the chart back of the perimeter 
facing the patient, as the semicircle of the perimeter 
faces him, and the chart will be in a position which 
will at once remove the difficulty. The meridians 
designated on the back of the perimeter will correspond 
to the reading on the circumference of the chart. 
For example, when the arm of the quadrant is at 
the 45th meridian to the right of either eye ex- 
amined, the 45th meridian on the chart to the right 
as the chart is held before one is the meridian sought. 
The most peripheral point on the quadrant at which 



64 METHODS OF EXAMINING FIELDS 

the patient can see the object can be read off from 
the back of the quadrant, and the mark is made on 
the 45th meridian on the chart at the degree desig- 
nated on the quadrant, reading from the center of the 
chart to the periphery. Example: The 45th meridian 
to the right of the right eye is under investigation. 
The patient sees the object at 50 degrees from the 
center. A mark is therefore made on the chart of the 
right eye at the intersection of the 50th degree and 
the 45th meridian. 

Campimeter Charts. — If the campimeter is marked 
in circles, the charts employed in perimetry may be 
used, or the author's campimetric chart may be 
substituted. If, however, the board is divided into 
squares, charts must be especially drawn as a facsimile 
of, or a miniature of the blackboard. The transfer 
of these fields to the chart will not give rise to any 
difficulty. 

Data to be Recorded on Charts. — Perimetry is 
but a handmaiden to ophthalmology. In itself it 
is incomplete, but when associated with certain other 
facts, it becomes indispensible. In addition to care- 
fully charting on the diagram changes which may be 
found, other data are essential to an intelligent inter- 
pretation: (1) central vision of each eye is of prime 
importance; (2) the ophthalmoscopic diagnosis, if 
possible, should be recorded; (3) the size of the test 
objects used and the character of the light — as to 
whether artificial or daylight, etc. — should be noted; 
(4) indistinct and irregular forms of scotomata will 
require a description; (5) the name of the patient, 
date, and reference to patient's history records should 
always be noted on the chart. 

Charts for Binocular Examination of the 
Fields of Vision by Means of the Stereoscope. — 
Dr. Ernest Haitz, of Germany, has recently devised 



CHARTS AND METHODS OF CHARTING 65 

stereoscopic cards for the study of binocular fields by 
means of the stereoscope. The cards are in yellow, 
blue, red, green, and white. Other charts are mapped 
out in a manner similar to the Bjerrum screen scale. 
The cards are adapted for use on any of the stereoscopes 
now in use. 



PART III. 

ANATOMY AND PHYSIOLOGY OF THE . 
VISUAL TRACTS. 

ANATOMY OF VISUAL TRACTS. 

Before taking up the study of the fields in morbid 
conditions, it is necessary to briefly review the anatomy 
and physiology of vision. 

Plate I is a diagrammatic sketch of the anatomic 
visual apparatus in man. The optic nerve enters the 
posterior pole of the eye 15 degrees to the inner side 
and a little above the point of central fixation or macula. 
In the disc there are no end-organs for light perception, 
but immediately beyond the disc's edge the various 
layers of the retina (the continuation of the optic 
nerve) are spread out over the interior of the eyeball. 
To the nasal side, above and below, the nerve fibers 
spread out in a regular manner; to the temporal side, 
however, the fibers traverse a greater area to reach 
the periphery, because they bend around the macular 
region which is supplied by direct nerve fibers from the 
papillomacular bundle of the optic nerve. The longer 
route of the temporal fibers has a bearing upon the 
earlier shrinkage of the nasal field in certain pathologic 
conditions. The retina is rather firmly attached at 
the point of entrance of the optic nerve and at the 
ora serrata. Between these points of fixation, it is 
very loosely connected with the underlying choroid. 
It is well to bear in mind this close attachment at the 
optic disc, because it will explain in a measure certain 
types of ring scotomata, as for instance, after commotio 
retinae, as suggested by Lohmann. 



PLATE I 




.._- Optic nerve 
.-.-Optic chiasm 
_. Infiindibulum 
Optic tract 

Cerebral 'peduncle 
Izf.c/f meat ate vody 

Ant. corp. qi/zrd. 

— - _ Thtvinar 
-~~-Ii/tcmal 'capsule 
Optic radiatio7i 



Diagrammatic Sketch of the Visual Path. 



ANATOMY OF VISUAL TRACTS 



67 



Rods and Cones. — The rods and cones, or per- 
ceptive end-organs, have a peculiar distribution. In 
the fovea, according to Saltzmann, 1 only cones are in 
evidence; beyond the fovea, in the macular region, 
rods appear; and receding from the macula toward 
the periphery, rods become relatively more numerous 
and the cones fewer in number, until the extreme 
periphery is reached, when cones are again in evidence 
in increasing numbers. In the macular region, each 
cone has a direct and individual communication with 
the primary optic centers, and possibly also the higher 




»- T 



Fig. 23. — Diagram illustrating distribution of the retinal nerve filaments. 

(Weeks.) 



optic centers, by being in contact with a single axis- 
cylinder or neuron, which is the prolongation of a 
ganglionic cell. Cones eccentric to the macular region, 
on the other hand, do not have the individual communi- 
cation, but a number of cones are in contact with a 
single axis-cylinder. This difference in anatomic 
structure accounts in part for the greater activity of 
vision of the macula over that of the peripheral retina. 
Blood Supply of the Retina. — The outer neuron, 
or rod and cone layer, receives its nourishment from 
the choroid, i. e., from the choriocapillaris. The other 

1 Anatomy and Histology of the Human Eyeball. 



68 



ANATOMY OF VISUAL TRACTS 



retinal layers are supplied by the main retinal branches 
of the central artery of the retina. The outer neuron, 
therefore, is distinctly separated in its blood supply 
from the middle and inner neurons, and is dependent 
upon the choroidal circulation for its activity. The 
great detour which the branches of the central artery 
of the retina must make in order to reach the extreme 
temporal region of the retina also has a bearing upon 




Fig. 24. — Distribution of the central artery of the retina. (Weeks.) 



the early loss of the normal field in certain pathologic 
conditions. 

The Optic Nerve. — The optic nerve proper extends 
from the retina to the chiasm. It is about 5 cm. in 
length; 3.5 cm. of it is within the orbit, and 1.5 cm. 
is within the optic foramen and the skull. The part 
within the sclera, or the free intra-ocular end of the 
nerve, is known as the disc or papilla. Within the 
papilla the nerve fibers are non-medullated, but from 



ANATOMY OF VISUAL TRACTS 69 

the eyeball to the chiasm the nerve fibers are medullated 
throughout. The relative position of the fibers from 
the retina is maintained in the optic nerve; that is, 
fibers from the temporal region of the retina occupy 
a temporal region in the nerve, those from the upper 
part of the retina are in the upper part or the nerve, 
etc. 1 In fact, this arrangement is present in the 
chiasm, and as we shall see, to some extent in the 
cortex of the brain. The nerve is covered by three 
sheaths which are continuations of the brain coverings, 
namely, the dural, the arachnoidal, and the pial 
coverings. The dural, or outer covering, is a hard 
membranous tissue attached to the sclera, and in part 
is continued forward as Tenon's capsule. At the optic 
foramen it is closely adherent to the periosteum. 
Between the pia and the arachnoid, and the arachnoid 
and the dura, are the subarachnoid and the subdural 
lymph spaces. These are continuous with the same 
spaces within the brain, and in increased intracranial 
pressure these spaces are frequently distended with fluid, 
a factor which enters into the production of papillitis. 

In the orbital cavity, the nerve lies loosely in the 
aerolar tissue, but in the optic foramen, accompanied 
by the ophthalmic artery, it occupies rather snugly 
this bony canal. At this point also it is in close juxta- 
position to the sphenoidal sinus, which is separated 
from it by a thin bony wall. These two points, the 
smallness of the bony canal or the optic foramen, 
and the proximity of the sphenoidal sinus, are pre- 
disposing factors in the easy production of retrobulbar 
neuritis. The analogue of this condition is found in 
the relation between middle-ear disease and inflam- 
mation of the facial nerve. 

1 Fuchs has called attention to the fact that the peripapillary region of the 
retina is supplied by fibers which are located in peripheral parts of the optic 
nerve. 



70 ANATOMY OF VISUAL TRACTS 

Papillomacular Bundle. — The optic nerve consists 
of numerous nerve fibers (estimated at 1,000,000) 
bound together in bundles. Centrally located, but 
indistinguishable in the normal nerve from the other 
bundles, is the papillomacular bundle which furnishes 
us with a direct path between the macula and the 
primary optic centers in the brain. In a normal nerve, 
these fibers are indistinguishable, but in certain forms 
of toxic amblyopia with central scotomata, degenera- 
tion of the optic tract has been traced from the eyeball 



Fig. 25. — Diagram showing position and shape of the papillomacular 
bundle of nerve fibers, A'-B'-C, the shape and position of the bundle A-B-C 
in the optic nerve. (Diagram suggested by Parsons.) 

up to the primary optic centers. From the primary 
optic centers the papillomacular path to the cortical 
macular centers is not so clearly defined. That such 
a path does exist, however, continuing from the primary 
optic centers to the cortical macular centers has been 
established beyond any reasonable doubt. (See Special 
Pathology of Fields, p. 182). The exact position of this 
macular bundle in the optic nerve is of some importance. 
As it leaves the eyeball it is situated to the outer side 
of the nerve, but as it approaches" the optic foramen 
it is fairly centrally located, a position which it main- 



ANATOMY OF VISUAL TRACTS 71 

tains in the chiasm, where the fibers divide with the 
other fibers of the nerve, and in the optic tract as far 
as the primary optic centers. The shape of the papillo- 
macular bundle is also of interest. Just back of the 
eyeball it is triangular in shape and is to the temporal 
side. Midway between the eyeball and chiasm it is 
round, and near the chiasm it is horizontally oval, 
about two to one. In the chiasm the oval appearance 
increases, and after it leaves the chiasm it again 
assumes a round appearance. 



R.O.T. 



Z.O.T. 




Z.O.N. 



Fig. 26. — Diagrammatic sketch of optic chiasm, showing crossed and un- 
crossed fibers: R.O.T., right optic tract; R.O.N. , right optic nerve; L.O.T., 
left optic tract; L.O.N. , left optic nerve. 



The Chiasm. — About 1.5 cm. of the optic nerve 
lies within the skull. At this point the nerves unite 
to form the optic chiasm. In man the fields overlap, 
and binocular vision includes a large part of our visual 
field. The number of crossed fibers in the chiasm is 
therefore relatively decreased. The relation of the 
crossed and uncrossed fibers, according to Weeks, is 
three to two. 

The immediate anatomic environment of the chiasm 
is quite as important as the chiasm itself. It rests 
in a groove of the sphenoid bone. Posterior to it 
is the sella turcica, in which rests the pituitary body. 
Directly in the posterior angle of the chiasm is the 



72 ANATOMY OF VISUAL TRACTS 

infundibulum, or process which connects the pituitary 
with the brain. Directly over the chiasm is the anterior 
tip of the third ventricle, and to either side are the 
internal carotid arteries. In this minute space, there- 
fore, are many important structures which frequently 
become the seat of disease, and the optic commissure 
is usually involved. 

Optic Tracts. — From the optic chiasm visual im- 
pulses pass along the optic tracts which are formed 
by the union of uncrossed fibers of one eye and crossed 
fibers from the opposite eye, including the papillo- 
macular bundle. The tracts bend around the outside 
of the cerebral peduncles and become a part of the 
midbrain structure as they pass into the primary 
optic centers, namely, the external geniculate body, 
the pulvinar, or the tip of the optic thalamus and the 
anterior corpora quadrigemina. It is claimed that at 
least 80 per cent, of the fibers of the optic tract pass 
to the external geniculate body. 

Primary Optic Centers. — The External Genic- 
ulate Body, Anterior Corpora Quadrigemina and 
Pulvinar.— It is unnecessary for our purpose to enter 
into a discussion of the exact functions of these 
centers. From pathologic studies it has been clearly 
shown that when the eyeball is removed, degeneration 
can be traced up to the primary optic centers and the 
centers themselves become atrophied. Experimentally, 
also it has been proved that a similar shrinkage of 
these centers occurs when the brain cortex in the 
region of the calcarine fissure on the same side of the 
brain is destroyed. As to whether the entire optic 
thalamus is concerned in vision, has not been definitely 
settled. The tail, or pulvinar, undergoes atrophic 
changes in the condition mentioned above, and this 
part of the thalamus at least is directly concerned in 
vision. 



ANATOMY OF VISUAL TRACTS 



73 



Communication of Primary Optic Centers with 
the Motor Nerves of the Eye. — Because of the 
multiplicity of tracts radiating from the primary optic 
centers through the optic radiations to the various 
parts of the brain, it is a difficult task to define the 




Fig. 27 




Fig. 28 
Figs. 27 and 28. — Diagrams showing higher optic centers in the brain. 
Fig. 27, the higher centers on the outer surface of the brain in the region 
of the angular gyrus. Fig. 28, the lower centers in the cuniform body, 
mesial surface of the brain. 



exact path by which the nuclei of the motor nerves 
of the eye communicate with the primary centers of 
vision. There can be no question, however, as to the 
presence of direct communication from these centers 
to the third nerve nuclei with which this subject is 



74 ANATOMY OF VISUAL TRACTS 

especially concerned. Studies of diseased processes, 
in the efferent and afferent paths of the reflex arc 
for light, of which the primary optic centers and the 
third nerve nuclei form a part, have without doubt 
established the existence of a direct path between 
these centers and the third nerve. The integrity of, 
or a break in, this arc has therefore been used as a 
focal symptom of value in locating a lesion. More 
recent studies, however, by Hess, Walker, and others, 
have shown that as a focal symptom at least, the integ- 
rity of, or break in, this reflex arc cannot be depended 
upon. The Wernicke pupillary phenomenon must 
therefore be held subjudice. (See Hemianopsia.) 

Paths to the Brain. — Tracing the paths from the 
retina to the primary optic centers has been much 
simplified as the result of diseased processes. Paths 
from the primary centers to the higher cerebral centers 
in the brain are attended with much difficulty. It is 
justifiable to conclude, however, from the numerous 
sources of information at hand, and making allowance 
for errors, that from the primary optic centers there is 
direct communication with the fore-, mid-, and hind- 
brain. This path of communication is established 
through the optic radiations. The bundle of nerve 
fibers collected from the primary centers passes through 
the extreme end of the internal capsule, and thereafter 
spreads into a fan-shape formation known as the optic 
radiations. So many reliable investigators have traced 
these paths that it is now generally accepted that a 
large number of fibers end in the cortical cells in and 
about the calcarine fissure. Others have been traced 
to the outer surface of the lobe as far as the angular 
gyrus. These latter so-called higher optic centers are 
without doubt an important part of the visual tract 
in man. From our present knowledge, gained by 
experimentation and by studies in morbid conditions, 



ANATOMY OF VISUAL TRACTS 75 

we are led to believe that this is the area of psychic 
blindness — a storehouse of memory pictures which aid 
us in properly interpreting and modifying the concept 
which is formed from the nerve impulses which are 
carried to the cells about the calcarine fissure. 
(See Plate II.) 

The Cuneus. — The triangular body in the posterior 
end of the hemisphere, known as the cuneus (see Fig. 
28), is generally accepted as the location of the higher 
optic centers; and while there is some difference of 
opinion as to the exact limitations of this area, nearly 
all concede that the higher visual centers which are 
directly concerned with sight are located in and about 
the calcarine fissure. This fissure is constant in man 
and is not one of the irregular and inconstant fissures 
merely the result of the convolutions. It is a sulcus 
of unusual depth and extends through the thin wall 
between the lateral ventricle, causing a distinct indenta- 
tion in that lymph space known as the hypocampus 
minor. Munk, 1 in experiments on animals, claimed 
that he "could map out the visual sphere in such a 
way as to represent the projection of the retina upon 
the brain." 2 It may be possible that this claim was 
established with insufficient data, but types of quadrant 
hemianopsia which have been reported in the literature 
tend to confirm these observations to this extent, 
that the upper parts of the retina are probably repre- 
sented in the upper part of the calcarine fissure, and 
the lower parts of the retina in the lower part of the 
calcarine . fissure. The macular centers are also defi- 
nitely located in the anterior part of the same fissure. 
At all events, the destruction of the cuneiform body 
causes blindness in corresponding halves of the retinae 
on the same side, a condition known as homonymous 
hemianopsia. 

1 Zur Physiologie der Gross-Hirnrinde. 2 Hill, in Norris and Oliver. 



76 ANATOMY OF VISUAL TRACTS 

THE PHYSIOLOGY OF VISION. 

Just what occurs in the visual act may be best 
explained by a study of Plate II, in which is graphically 
and beautifully represented the visual act in a diagram- 
matic sketch, as suggested by Lohmann. 

He divides the act into (a) a physical phase, which 
I have called a physicochemical phase. This includes 
the dioptric parts of the eye and the receptive end- 
organs of the retina, or rods and cones sensitized 
by the visual purple, (b) The physiologic phase, or 
that part of the optic tract from the rod and cone 
layer of the retina to the cortical or higher centers in 
the hemispheres, in which the light stimulus is trans- 
formed into a nerve impulse, (c) The psychologic 
phase, which takes place in the cortex of the brain. 

Physicochemical Phase. — Perimetry is only 
indirectly concerned with the dioptrics of the eye. 
One must take into consideration refractive errors of 
considerable degree, as such errors, if not corrected, 
may interfere with the proper "taking" of the field. 
The purely physicochemical act must, however, be 
thoroughly understood in order to correctly interpret 
abnormalities. 

Accommodation. — The eyeball may be looked upon 
as a camera containing a dark chamber with an aper- 
ture in front — the pupil — the size of which may be 
controlled to meet conditions. Rays of light entering 
through this opening project upon the retina an 
inverted image. Through the medium of accommoda- 
tion the image becomes sharply fixed upon the retina. 
This act of accommodation or adjustment of the eye 
for varying distances, is brought about by contraction 
and relaxation of the circular fibers of the ciliary 
muscle. When the ciliary muscle is at rest, the zonule 
of Zinn tightens, and acting on the lens tends to flatten 



PLATE II 




Diagrammatic Sketch of the Physiology of Vision. 
(After Lohmann.) 

GREEN — Physieoehemieal phase of vision. 

RED — Physiologic phase or transformation of light stimulus into 
nerve impulse. 

BLUE — Psychologic phase. 



THE PHYSIOLOGY OF VISION 77 

it. In this position in the normal eye parallel rays are 
focussed upon the retina. When, however, in the act of 
accommodation the circular fibers of the ciliary muscle 
contract, the suspensary ligament, or zonule of Zinn, 
relaxes and the lens, by its own elasticity and that of 
its capsule, increases in its anteroposterior diameter 
— and objects nearer than infinity may be focussed 
upon the retina. This is accommodation. 

The Rod and Cone Layer. — To continue our analogy 
of the camera, the rod and cone layer of the retina 
may be regarded as the plate or film upon which the 
impression is to be made. The photographic plate 
is made sensitive to impressions by chemical processes. 
In the human eye similar conditions obtain, but the 
process is more complicated, as the chemistry of the 
body is always complex. The rods and cones must 
become sensitized. This is accomplished possibly by 
the " visual purple." It has been shown, for example, 
that the eye exposed for some time to an intensely 
bright light, sees nothing for a considerable period 
after being admitted to a dark room. The visual 
purple in this instance has been exhausted, and the 
eye is "npn-adapted. " After a time, the eye recovers 
"adaptation" and objects in a darkened room may be 
distinctly seen. The effects of light, therefore, upon 
the retina bring about a chemical change, or dis- 
organization, which in time recovers itself. While 
not entirely beyond question, it is generally believed 
that the visual purple is the chemical substance upon 
which light acts and that it is the substance which 
renders the rods and cones sensitive. 

Between this physicochemical phase of vision and 
the purely physiologic phase, a connecting link is 
necessary. A light stimulus must be converted into a 
nerve impulse. Just how or where this transition 
takes place is an unsettled problem and difficult to 
determine. 



78 ANATOMY OF VISUAL TRACTS 

In the lower animals it has been shown that light 
thrown upon the retina brings about a shifting or 
change in the rod and cone elements. The rods become 
elongated and the cones become thickened. Such 
changes cannot be demonstrated in the human eye 
for obvious reasons, and it is generally thought that 
changes of this character do not take place. A more 
important change in the retina caused by the light is 
the bleaching of the visual purple. A fresh retina 
exposed to light very quickly loses its pinkish hue. 
At all events, there is evidence to lead one to believe 
that light produces a chemical change, either in the 
visual purple or in some other chemical substance which 
has the power of recovering itself. The cones do not 
contain visual purple. It is limited entirely to the rods. 
In the fovea, therefore, where only cones exist, there 
is no visual purple; and although this is the part of 
the retina in which acuity of vision is most marked, 
it is not as well adapted for night vision as other parts 
of the retina which contain rods. Lohmann therefore 
concludes, although not unreservedly, that the trans- 
ferring of light stimulus into a nerve impulse is probably 
a photochemical process. It is probable at least that 
the visual purple is an essential factor in the trans- 
forming of the light stimulus into a nerve impulse. 

Physiologic Phase. — Just where the physicochemical 
phase ends and the physiologic phase begins is equally 
interesting. Salzmann 1 divides the retina into three 
cellular layers: (i) the outer or rod and cone neuron; 
(2) the inner nuclear neuron; (3) the ganglionic neuron. 
We have discussed the first or outer layer. The 
physiologic phase of vision probably begins with the 
second or inner neuron. I believe it to be more 
accurately correct to speak of the inner neuron as the 
point of transition of the physicochemical to the physio- 

1 The Anatomy and Histology of the Human Eyeball in the Normal State. 



THE PHYSIOLOGY OF VISION 79 

logic phase. This would correspond to conditions as we 
find them in the spinal cord. The ganglionic cells would 
coincide with the ganglionic cells of the cord. The 
present tendency is to consider a neuron as consisting 
of a cell with a prolongation or axis-cylinder. As to 
whether the nerve elements are in contact, as viewed 
by Ramon y Cajal, or the axis-cylinder is a continuation 
of the cell, as claimed by Apathy and others, is unim- 
portant for our purposes. Atrophy has been limited 
to any one of these neurons, and this would tend to 
confirm the former theory. Little is definitely known 
about the exact functions of the inner nuclear layer, 
but all concede that this neuron serves as a connecting 
link of the various nerve elements, and processes of a 
high order take place within this layer. (Salzmann.) 
The third, or ganglionic neuron, therefore, we will re- 
gard as the actual beginning of the physiologic phase 
of vision. It is in contact with the inner nuclear 
layer by short processes, and the axis-cylinders extend 
from the ganglion cells to the primary optic centers 
at the base of the brain — the external geniculate 
body, the anterior corpora quadrigemina and the tail 
of the optic thalamus. It is possible that this neuron 
is continuous even with the cortical cells in the cuneus. 
Studies of diseased or atrophic paths after enucleation 
have traced these parts as far as the primary centers — 
but so far as I know, we cannot say definitely that 
there is an uninterrupted path from the ganglionic 
cells in the retina to the brain and cortex. 

Light stimulus, which now has been transformed 
into a nerve impulse, travels along the axis-cylinders, 
through the optic nerve, chiasm, and the optic tract 
to the primary optic centers. After enucleation of the 
eyeball, and after removalof the occipital lobe, atrophic 
changes have been found in the external geniculate 
body and in the pulvinar, and to some extent in the 



80 ANATOMY OF VISUAL TRACTS 

anterior corpora quadrigemina. A number of workers 
have failed to confirm these findings, but they have 
been observed by so many reliable investigators that 
we must conclude that these bodies, or centers, are 
directly concerned with the physiologic phase of vision. 

Tracing the various tracts through the brain has 
met with some difficulties, which thus far have, not 
been surmounted, and it will be best and less confusing 
to limit our discussion to what has been conceded as 
definite knowledge. Impulses travel through the optic 
radiations from the primary centers to the cortex, 
in and about the calcarine fissure of the cuneiform 
body. Here the physiologic phase of vision ends and 
the psychologic phase begins. 

Psychologic Phase of Vision. — The visual centers 
of the brain, exclusive of the basal ganglia, called 
higher visual centers, are grouped (a) as lower visual 
centers, and (b) as higher visual centers. The lower 
centers are located in the cortex of the calcarine 
fissure, and the higher centers are distributed through 
the surface of the occipital and parietooccipital cortex, 
especially in and about the angular gyrus. Lesions of 
the calcarine fissure cause hemianopsia, homonymous 
in type. Lesions about the angular gyrus bring about 
a condition known as mind-blindness. In this state 
the patient sees the object, but has no memory pictures 
with which to compare his sensations. He therefore 
loses his power of interpreting his sensations. He is, 
as Munk says, " psychically blind." We may infer 
from this how complex is the psychologic phase of 
vision. Our conception of what we see is modified by 
past experiences. This memory storehouse is located 
on the outer surface of the posterior part of the brain 
in the neighborhood of the angular gyrus. We therefore 
locate the psychologic phase of vision in the posterior 
part of the cerebral hemispheres on the outer and 



THE PHYSIOLOGY OF VISION 81 

mesial surfaces. It is reasonable to suppose, however, 
that even other parts of the brain are concerned with 
this phase of the visual act. 

With this brief resume of the generally accepted 
facts of the anatomy and physiology of vision, we are 
prepared to take up the study of the changes which 
take place in diseases of the visual tract. 



PART IV. 

GENERAL PATHOLOGY OF THE VISUAL 

FIELD. 

The pathologic changes which one notes in examina- 
tion of fields are of a twofold character: (i) scotomata, 
or blind spots; (2) changes in the size and shape of 
form and color fields. Either one of these changes 
may be observed in a given case, or they may be found 
in combination. 

SCOTOMATA. 

A scotoma is a blind spot which appears in the 
visual field. The blind spot of Mariotte is the only 
area in the field of the normal eye which may be 
regarded as normal, as it represents the entrance of the 
optic nerve into the eyeball — an area in which the rod 
and cone elements are absent. Any other areas within 
what may be regarded as normal limits of vision for 
a given patient are pathologic, and represent altera- 
tions in function or structure of the optic nerve, retina, 
or choroid. They may be small or large, regular or 
irregular in outline, distinct or indistinct, as the lesion 
which causes them will determine. 

Relative and Absolute Scotomata. — In order 
to be specific in describing the character of a blind 
spot, we classify scotomata, first, as relative and 
absolute. A relative scotoma is an area in which form 
may be seen, but in which one or more of the colors — 
blue, red, or green — are not recognized. The uniform 
method of charting a relative scotoma is represented 
in Fig. 29, A. Parallel lines are drawn in one direction 
only. 



SCOTOMATA 



83 



An absolute scotoma, on the other hand, is a blind 
area in which the patient can perceive neither form 
nor color. It is a totally blind area. In charting this 
form of blind spot, it is universally drawn as in Fig. 
29, B. When charted in this manner, it needs no other 
description. 

The difference between a relative and an absolute 
scotoma is practically one of degree. In the course of 
disease, if the process is not too sudden or acute, a 
relative scotoma develops first, and as the disease 
progresses, an absolute blind spot is formed. In 



LEFT 



RIGHT 




Fig. 29. — A, central scotoma. Method of charting a relative scotoma. 
B, paricentral scotoma. Method of charting an absolute scotoma. 

recovery, too, before function is completely restored, 
an absolute scotoma will become relative ; or if recovery 
remains incomplete, a relative blind spot may remain. 
The completeness or incompleteness of the blind spot 
therefore enters not only into the diagnosis but into 
the prognosis as well. 

Indistinct Scotomata. — Occasionally a scotoma is 
indistinct in outline, i. e., the patient will not be able 
to define a sharp line of demarcation between the 
point of clear vision and the absence of vision. In 
relative scotomata, this is especially well illustrated. 



84 GENERAL PATHOLOGY OF THE VISUAL FIELD 

In a blind area for green, for example, the color does 
not sharply disappear as the blind spot is approached, 
but shades off into a paler color, becomes white, and 
finally is lost. The periphery of the scotoma therefore 
is surrounded by an indistinct zone and we speak of 
this as an indistinct scotoma. The entire blind area 
may be of the same general character in which green, 
for example, may not be recognized as a color, or in 
fact, in which form is hazy and uncertain. This form 
of scotoma should likewise be classified as an indistinct 
scotoma, and the terms relative and absolute should 
be reserved for the classification given above. In fact, 
great care and exactness in the choosing of terms which 
we employ for describing definite conditions is essential 
to a clear interpretation. A more correct classification 
as to degree would be indistinct, relative, and absolute 
scotomata. Such a classification, if generally accepted, 
would save much confusion. It is the classification 
which will be maintained throughout this digest on 
perimetry. 

Positive and Negative Scotomata. — A second 
classification is that of positive and negative scotomata 
— a classification which is frequently confounded with 
that of relative and absolute. The characteristics here 
are totally different. A positive scotoma is a blind 
area in the visual field which the patient seesentoptically 
— a black or gray area which the patient can clearly 
outline, and of which he will complain when the 
oculist is consulted. A negative scotoma, on the other 
hand, is not recognized by the patient, and is only 
elicited by careful examination on the perimeter. A 
positive scotoma may in time become negative, i. e., 
after a considerable period of time the patient may 
become so accustomed to the presence of the blind area 
that he is no longer conscious of it. Floating masses 
in the vitreous give rise to positive scotomata in the 



SCOTOMATA 85 

visual field, but in time they may disappear from the 
patient's consciousness, and no longer interfere with 
vision. The classification, however, has a deeper 
significance. Positive scotomata usually mean a 
lesion, or lesions, which prevent the formation of an 
image on the rod and cone neuron, as, for example, 
a dense hemorrhage in the retina or vitreous, disturb- 
ance of the choroidal circulation, or circumscribed 
disease of the choriocapillaris which supplies nourish- 
ment to the rod and cone elements. Under these 
circumstances, the blind area is likely to be positive. 
On the other hand, a negative scotoma usually is 
associated with disease of the neurons, the ganglionic 
elements, or of the axis-cylinders. In recent cases 
this location of the lesion by the positive or negative 
character of the blind area may, in a majority of cases, 
be depended upon. In cases of long standing, however, 
a positive scotoma may become negative, as explained 
above. 

It must be clear also that negative scotomata may 
be either relative or absolute. 

Central, Paracentral and Peripheral Scoto- 
mata. — A third classification may be made in reference 
to position, that of central and peripheral. A central 
scotoma is one which includes the macula, a condition 
which is common in retrobulbar neuritis or toxic 
amblyopia in which the papillomacular bundle of 
nerve fibers is diseased. Peripheral scotomata, as the 
name implies, are found in peripheral parts of the 
retina. . When in the center or intermediate zone, 
that is up to the 40th degree from the center, they are 
readily recognized by perimetry; but when in the 
extreme periphery, where the retinal elements require 
strong stimulation in order to receive a visual impres- 
sion, they are often overlooked unless searched for 
carefully. Scotomata in the central zone may be sub- 



86 GENERAL PATHOLOGY OF THE VISUAL FIELD 

divided into pericentral (around the macula) or para- 
central (alongside of the macula). Because of the 
supposed double innervation of the macula (repre- 
sentation on both sides of the brain) the macula may 
escape. 

Enlargement of the Normal Blind Spot of 
Mariotte. — Under certain conditions, the normal 
blind spot of Mariotte becomes enlarged and is 
pathologic. It will vary, naturally, within certain 
normal limits which will be determined by the size 
of the optic disc. As a rule, it is oval in shape, with the 
long axis at 90 degrees. When but one eye is the seat 
of disease and the other is normal, the normal eye 
furnishes a standard by which to judge of the patho- 
logic or normal extent of the blind spot in the affected 
eye. The enlargement will depend upon the extent 
of the process in and about the papilla. Not infre- 
quently, if the process extends toward the macular 
region, the scotoma will gradually increase in size 
until the macula is reached, when it becomes a central 
scotoma. The conditions under which this enlarge- 
ment may take place will be discussed under special 
pathology of the fields. 

Van der Hoeve, in his studies of the normal blind 
spot, has found the average size to be 5 degrees by 
7 degrees. In my own studies, made previous to the 
reading of his paper, I found exactly the same measure- 
ments. The most frequent deviation from the normal 
average I found to be in the vertical diameter. I 
have not, however, been able to confirm Van der 
Hoeve's ring of indistinct scotoma surrounding the 
normal blind spot in a normal individual. 

In pathologic conditions, the first evidence of enlarge- 
ment is an indistinct band surrounding a blind spot 
of normal size. In this zone colors do not have their 
normal value, but appear paler and frequently become 



SCOTOMATA 



87 



white before they are lost in the blind spot. In a 
later stage, the blind spot may be normal for form but 
enlarged relatively for one or all colors, and beyond the 
relative area an indistinct zone will again be found. A 
third type of enlargement is an absolute enlargement 
for form and color. Invariably the color loss is dis- 
tributed over a larger area than that for form, and 
quite as uniformly is the indistinct zone to be found 
beyond the limits of the color loss. These observations 
cannot w T ell be determined on an arc perimeter. 




Fig. 30. — A ring scotoma of syphilitic origin. Enlarged blind spot of Mariotte. 

Ring Scotomata. — Under certain conditions a 
scotoma, or blind spot, may take the form of an 
irregular circle, peripheral and central vision remaining 
clear. This form of visual defect usually is found in the 
inte.rmedi.ate zone between the 15th and 30th degrees. 
Much thought has been given to the reasons for the 
formation of this defect. It is in this zone that the 
short ciliary 7 arteries terminate, and this factor, together 
with the peculiar arrangement of the choriocapillaris, 
probably more than any others, gives rise to the ring 
scotomata. The exact manner of formation is unsettled. 



88 GENERAL PATHOLOGY OF THE VISUAL FIELD 

This scotoma rarely develops as a ring primarily, but 
island-like blind areas are first in evidence. These 
enlarge, and finally coalesce to form a complete or 
incomplete area of blindness about the point of central 
fixation. Instead of completely circling the macula, 
a healthy choroid and retina may extend in one 
area from center to periphery, forming thereby a 
horseshoe-shaped scotoma (see Fig. 30). When re- 
covery takes place, the ring scotoma again resolves 
itself into islands, and if recovery is incomplete, 
multiple scotomata may remain to mark the site of the 
ring scotoma. This type of blind spot is usually of 
vascular origin. Syphilitic choroiditis is a common 
pathologic factor. Other general and constitutional 
diseases which produce vascular changes are also 
frequently associated with this type of blind spot. It 
may be assumed, therefore, that the choroidal circula- 
tion is usually at fault, and rarely the neuron elements. 




Fig. 31. — Homonymous hemianopsia. 




Fig. 32. — Quadrant anopsia. 



SCOTOMATA 



89 




Fig. 33.— Altitudinal hemianopsia. 




Fig. 34. — Bitemporal hemianopsia. 




Fig. 35.— Binasal hemianopsia. 
Figs. 31-35. — Types of anopsias. 

In commotio retinae a ring scotoma may be formed. 
The retina is firmly attached to the sclera at the 
entrance of the optic nerve and at the ora serrata. 
Between these points of fixation the retina is loosely 
attached to the underlying tissues; and the formation 
of a ring scotoma therefore, as pointed out by Lohmann, 
is easily understood, as circulatory disturbances or 



90 GENERAL PATHOLOGY OF THE VISUAL FIELD 

detachment may occur between, or at some distance 
from, the optic nerve and ora serrata. 

Instead of disease of the retina and choroid, ring 
scotomata may have their origin in the optic nerve, 
the chiasm or the brain. Under these circumstances, 
one or both eyes may be involved; the location of the 
lesion in each instance will determine this fact. 

Quadrant and Hemianopic Scotomata. — Anop- 
sias. — Disease of the visual path in the chiasm and 
in any part posterior to the chiasm is characterized 
by certain field changes known as anopsias. They 
usually are bilateral changes, although rarely in 
chiasmal disease but one eye may be affected. As a 
rule corresponding retinal parts are involved. When 
an entire half-field is blind, the condition is one of 
hemianopsia. When but a quarter of the field is 
blind the condition is known as quadrant anopsia, 
right or left, superior or inferior. The anopsias are 
homonymous in type when the right or left half of each 
field is blind, heteronymous when the temporal halves 
or nasal halves are involved. Blindness in both 
temporal fields is known as bitemporal hemianopsia 
and in both nasal fields as binasal hemianopsia. 



LEFT 



RIGHT 




Fig. 36. — Dividing line close to center. 



SCOTOMATA 



91 



RfGHT 




Fig. 37. — Oblique dividing line. 

o ,.o 



RfGHT 




Fig. 38. — Macular area and area beyond macula intact. 



RfGHT 




'so — iqo 

Fig. 39. — Overshot fields. 



Figs. 36-39. — The dividing line of homonymous hemianopsias. 



92 GENERAL PATHOLOGY OF THE VISUAL FIELD 

Anopsias may develop from the periphery toward 
the center or they may begin as homonymous or 
heteronymous scotomata in the central field, and 
spread toward the periphery 7 , or both processes may 
be combined. 

Instead of a lateral division of the blind and seeing 
parts of the retina, the dividing line may be horizontal. 
When the upper or lower, half is blind, the anopsia is 
known as altitudinal hemianopsia, superior or inferior. 

Anopsias may be indistinct, relative or absolute, 
negative, and more rarely, positive. 

Line of Demarcation. — The dividing line, or line of 
demarcation, between the seeing and blind parts of the 
retina is best determined by Bjerrum's method, a 
small (i to 3 mm.) test object being used. Because of 
individual anatomic differences in the distribution of 
the crossed and uncrossed nerve fibers in the chiasm, 
the dividing line will not be the same in all cases. 
In Fig. 36 the line of demarcation is straight and 
passes close to the center. In Fig. 37 the dividing 
line is oblique. Either of these types may be found, 
and they are due to this anatomic difference of which 
I have spoken. Again, because of the double innerva- 
tion of the maculae, a hemianopsia may pass around 
the macula, as in Fig. 38, or we may find " overshot" 
fields, as shown in Fig. 39. In this type of field, 
not only are the maculae intact, but the field above 
and below the macula is preserved because of the 
anatomic abnormality of the distribution of the crossed 
and uncrossed fibers. 

Significance of Overshot Fields. — Careful studies of 
overshot fields, show that color fields extend practially 
to the extreme edge of the form field, or near the divid- 
ing line. This, therefore, would exclude the possibility 
of a partial or incomplete disturbance of the visual 
centers and would tend to confirm the conclusion that 



SCOTOMATA ' 93 

not only the macula, but other parts of the retina, may 
be preserved under these circumstances. In a case 
recorded by Wilbrand, 1 the overshot area included 
not only the maculae, but to the same extent the 
retina above and below the maculae. This occurred 
in a woman, twenty-four years of age, who suffered 
from complete right-sided hemianopsia from early 
childhood. At autopsy the left occipital lobe was 
found to be a " crumbling mass," and descending 
atrophy was observed in the left optic tract deep into 
the chiasm, showing that the overshot field bore a 
direct relation to the centers and conducting path. 
The overshot field, whether it includes the macula 
alone or other parts of the retina, has important sig- 
nificance, especially in right-sided hemianopsia. For 
example, when the line of separation passes through, or 
close to the center, a patient suffering from right-sided 
hemianopsia will have difficulty in reading, because 
each letter, as it were, is hidden from view until the 
macula is turned upon it. Reading is therefore tedious. 
When, however, the field is overshot, this difficulty 
is largely eliminated, just as it is in left-sided homony- 
mous hemianopsia. 

Incomplete Hemianopsia. — As most forms of homony- 
mous hemianopsia are due to disease within the brain, 
and the optic centers and tracts are distributed over a 
considerable area, hemianopsias as a rule are irregular 
and incomplete when they first make their appearance. 
In fact, this incompleteness argues for the central 
origin of hemianopsia rather than that of the tract and 
chiasm. The color hemianopsias alone are infrequently 
observed. They do occur, however, and when present 
tend to confirm the fact that there are separate centers 
in the brain for colors, and possibly separate conducting 
paths. Color hemianopsia, complete or incomplete, 

1 Norris and Oliver, ii, 279. 



94 GENERAL PATHOLOGY OF THE VISUAL FIELD 

without disturbance of form, originates in the higher 
cerebral centers in and about the cuneiform body or 
in the optic radiations, as even minute lesions in other 
parts of the visual path will give rise to complete forms 
of half- vision. 

Scotomata Associated with Peripheral Field Changes. 
— The various forms of scotomata thus far described 
may or may not be associated with the second type 
of change in the field, namely, alteration in form and 
color fields. For example, in toxic amblyopia, one may 
find the classic central scotoma together with con- 
traction of form and color fields; and in hemianopsia, 
instead of normal fields in the seeing half, one may 
find shrunken fields, especially when the lesion is near 
to or in the chiasm. Again, a lesion in the posterior 
part of the brain, especially neoplastic in origin, may 
be so large as to give rise to increased intracranial 
pressure. Under these circumstances, in addition to 
the direct focal symptom of hemianopsia, the general 
symptoms, papilledema and optic neuritis, may cause 
a contraction of form and color fields in the part of 
the field which is unaffected by the hemianopsia. 

The presence of hemianopsia does not eliminate the 
possibility of hysteria in the same patient. In addition, 
therefore, to the symptom of hemianopsia, one may 
find those of hysteria. The same rule applies to all the 
various changes which may be found in a patient 
suffering from combined systemic disease and inde- 
pendent conditions which may cause hemianopsia. 

CHANGES IN FORM AND COLOR FIELDS. 

Three types of changes are found in the shape and 
size of the fields: (i) there may be a concentric con- 
traction of the field; (2) in addition to the concentric 
contraction, one or more parts of the field may show 



CHANGES IN FORM AND COLOR FIELDS 



95 



angular or irregular areas of greater shrinkage; (3) 
the field for the most part may be normal, and a large 
irregular angular defect may extend in one area, even 
to the point of fixation. All irregularities in the form 
fields will fall under one of these divisions. 

Concentrically Contracted Field. — An uncom- 
plicated, or primary optic atrophy furnishes the best 
example of concentric contraction of form and color 
fields. In the early stages of the disease there will be 
found moderate and equal contraction of the form 
field in all directions. Color fields are also reduced, 




Fig. 40. — Concentrically contracted field of primary optic atrophy. Green 

field totally lost. 



at times relatively, but more frequently out of propor- 
tion to the form field. The essential feature is the 
concentric contraction. For example, in Fig. 40 the 
form field is contracted approximately to 50 degrees on 
the temporal side, and red is recognized at 30 degrees, 
whereas green has entirely disappeared from the 
field. Blue, on the other hand, is nearly as large as the 
form field. As pointed out earlier, blue is not involved 
so early in neuritic diseases as in chorioretinal dis- 
turbances. The reverse is true of red and green. 
In fact, in primary optic atrophy, shrinkage in the 



96 GENERAL PATHOLOGY OF THE VISUAL FIELD 

red and green fields may be apparent before the form 
field has diminished in size. This is true when the 
field is taken in a good daylight. In reduced light, a 
contraction of the form field may be clearly demon- 
strated, while red and green will show a relatively 
greater reduction. The concentric element in the con- 
traction, however, is the chief characteristic of this 
type of change. When present, it means an evenly 
distributed atrophy or disease of the optic nerve. 

Concentric Contraction Plus Unequal Defects. 
— The second type of contraction is found most typical 




Fig. 41. — Irregular contraction of optic neuritis. Loss of upper field with 

general contraction. 



in optic neuritis. In this condition, while the entire 
nerve is the seat of disease, an area may show greater 
destruction, and the field will show one or more re- 
entering angles of contraction. This type of field is 
probably the one most frequently observed, as one 
rarely sees an evenly diffused inflammation of the 
optic nerve. Furthermore, the peripheral parts of the 
retina are not equally sensitized for two reasons: 
(i) anatomically, both blood and nerve supply is more 
direct and shorter to the nasal side of the retina than 
to the temporal side. Hence, in glaucoma, whether 



CHANGES PECULIAR TO COLORS 97 

acute or chronic, one might expect to find a concentric 
contraction, but as a rule the nasal field is always the 
first to show shrinkage; (2) the rod and cone elements 
on the nasal side of the retina are in greater activity 
and more readily open to impressions than the temporal 
elements because of being in more constant use. A 
somewhat irregular field, therefore, is most frequently 
observed. The behavior of the color field in this in- 
stance is not unlike that of the first type, i. e., the 
color fields follow the form fields rather regularly, 
showing only a somewhat greater degree of shrinkage. 
Normal Fields with Reentering Angle. — Pos- 
sibly the third type of change might be considered an 
advanced stage of number two. As a matter of fact it 
may eventually assume pretty much the same character- 
istics as the second type, but primarily it is distinct (see 
Fig. 70). It is well illustrated in glaucoma, in phlegmon 
of the orbit or in disease of the sphenoidal accessory 
sinus. The sphenoidal sinus is separated from the optic 
nerve in the optic foramen by a thin partition of bone. 
In disease of the sphenoid a localized inflammation 
of the nerve will therefore mark the beginning of what 
will become diffused optic neuritis, and the. type of 
field under discussion may be observed. Disease of the 
orbital tissues along the course of the optic nerve, or 
even in the chiasm, may produce the same type of 
field. As a rule the condition is unilateral, unless both 
orbital cavities are involved or disease of the chiasm 
develops. It signifies focal disease in the course of the 
optic nerve or chiasm, or more rarely of the tract. 
As a rule, color defects of a similar character will be 
observed. 

CHANGES PECULIAR TO COLORS. 

Contraction of the form fields shows the degree of 
disease of the visual tract. It is better evidence of the 

7 



98 GEXERAL PATHOLOGY OF THE VISUAL FIELD 

real condition of the visual path than an ophthalmo- 
scopic study can possibly furnish. The evidence is 
minute and analytical. The color fields and color 
changes, however, furnish a more delicate test in the 
early stages of the disease and at times furnish the 
clue to the seat of trouble before an appreciable change 
has taken place in the form field. Lohmann quotes 
Kollner's observation of green vision in a patient for 
weeks before retinal detachment occurred. Color 
changes in general are earlier than those for form, 
and a careful study of the behavior of colors in various 
parts of the field has increased the clinical value of 
perimetry both in diagnosis and prognosis. Studies 
in color fields show, for example, that blue is more 
clearly observed in indirect vision than in the macula. 
A red object 2 mm. in diameter can be clearly defined 
in a good light at 20 feet. A 5 mm. green object 
may be recognized at the same distance, while but 
few patients can recognize a blue object 7 mm. in 
diameter at this distance. When, however, a 7 mm. 
blue object is placed 6 inches eccentric to the point 
of fixation, it can be clearly recognized as blue at 
20 feet. , 

In diseased conditions, this peculiarity of the behav- 
ior of colors becomes accentuated and, paradoxical 
as it may seem, the blue defects may be observed in 
central vision earlier than in the periphery. It is 
a matter of observation also that blue and yellow 
changes may be the earliest changes noted in disease of 
the retina and choroid, i. e., in disease of the neuro- 
epithelium, red and green contraction is a much later 
phenomenon than that of blue and yellow. In disease 
of the conducting paths and centers, on the other 
hand, blue and yellow may be preserved after red 
and green have been lost, or at all events, shrinkage 
of the blue and yellow follows that of red and green. 



CHANGES PECULIAR TO COLORS 99 

Inversion of Color Fields. — Under certain condi- 
tions, usually functional in type, the order of the size 
of color fields is reversed. For example, in hysteria, 
the green field may extend beyond the limits of the 
red field throughout, or more frequently the size of 
the red and green fields will be the same. Red and 
green reversal, or interlacing, may be looked upon as 
functional in origin. Reversal of blue and red or blue 
and green, however, may be, and usually is, organic 
in origin, or at least, if functional, is due to circulatory 
disturbance. In chorioretinal disease, for example, 
especially when the elements of edema are present 
in the retina as in chronic interstitial nephritis, the 
blue field may be contracted within the limits of the 
red, and even the green, (de Schweinitz and others 
claim the blue-red inversion is quite as common as the 
red-green inversion, and that the red field in particular 
is apt to be enlarged.) If, however, the blue-red or 
blue-green inversion is a symptom of hysteria, other 
ocular symptoms of hysteria may be present as, for 
example, tubular fields, and the eye-ground will be 
negative. A type of apparent or partial interlacing 
of the color fields may be due to lack of care in taking 
the fields. The patient's head may be allowed to shift, 
or the eyes may wander so that the position has not 
been the same throughout the examination. Most 
incomplete or partial reversals of color fields may be 
found to be due to this cause; and when such a field 
is developed, the field should be reexamined carefully 
to avoid this source of error or to confirm the correct- 
ness of the field. 

Tubular Fields. — Under normal conditions, when 
the patient's eye under examination is removed farther 
and farther from the central object on the perimeter, 
the field will increase proportionately in size. The 
angle of vision is the same, but the base of the triangle 



100 GENERAL PATHOLOGY OF THE VISUAL FIELD 

which the angle subtends will increase with the length 
of the sides of the triangle. 

If A in Fig. 42 represents the width of the field 
at 33 cm., at 1 meter the field is represented by B, 
at 2 meters by C. In hysteria, instead of a normal in- 
crease in the size of the fields, approximately the same 
size will be developed for all distances, even up to 
2 meters. In fact, in this condition, form and color 
fields may appear to be the same size. This is not the 
result of malingering on the part of the patient, even 
though it may seem so to the casual observer. It is 
in entire keeping with the general symptomatology 
of hysteria, i. e., the element of inhibition dominates 




EYE 



2M 

Fig. 42. — Diagram illustrating the size of the field at distances of \ meter, 
1 meter, and 2 meters. 

the patient's conduct throughout. This type of field, 
together with other symptoms will be more fully 
discussed in the chapter on Functional Nervous 
Diseases. 

Fatigue Field. — A condition of exhaustion is 
readily manifested in the study of fields. Even in 
a normal case, too prolonged an examination will 
develop a field modified by exhaustion. In low 
asthenic states, and especially in pronounced neuras- 
thenia, a type of field may be developed which 
differs from all other changes and is characteristic 
of neurasthenia. The most typical form of field in this 
condition is known as a spiral field. The rods and 



CHANGES PECULIAR TO COLORS 



101 



cones in the peripheral parts of the retina are first 
affected in asthenic states, and the condition gradually 
increases toward the center as the state of exhaustion 
increases. When, therefore, a field is taken, the first 
points examined may approximate the normal in size, 
but as the examination continues, the evidence of 
exhaustion becomes more and more pronounced, as 
shown by the increasing contraction of the field. If 
the examination is repeated several times, the bound- 
ary lines of the field will assume the shape of a spiral 




Fig. 43. — Spiral fatigue field of von Reuss. (Weeks.) 



curve, growing smaller as the examination is continued. 
Such a field is represented in Fig. 43. 

In the normal patient, the field tends to enlarge 
with each successive examination, or as the patient 
develops a better understanding of what is expected 
of him in the taking of the field. However, if the 
examination is continued for too long a period, so 
as to cause physical tire, the field may show a slight 
tendency to contract as the result of normal tire. 

Scintillating scotomata, photopsias, etc., will be dis- 
cussed in the chapter on Functional Nervous Diseases. 



PART V. 

SPECIAL PATHOLOGY OF FIELDS. 

A study of changes observed in specific instances of 
organic disease can be made most systematically by 
dividing the visual tract into: (a) the intra-ocular 
portion, including the choroid, retina, and nerve head; 
(b) the optic nerve proper; (c) the chiasm; (d) the 
intracerebral portion, including the optic tracts, 
primary optic centers, optic radiations, and the cortex 
concerned in vision. This division of the visual tract 
is a natural one, anatomically, physiologically, and 
pathologically. 

DISEASES OF THE INTRA-OCULAR PORTION OF 
THE VISUAL TRACT. 

It is a difficult matter in most instances to draw a 
sharp dividing line between diseases of the choroid 
and retina. In fact, one does not think of disease of 
the choroid without a secondary retinal involvement. 
As pointed out in the anatomy and physiology of 
the visual tract, part of the function of the choroid 
is to supply nourishment to the neuro-epithelial layer 
of the retina. Disturbance of function in one implies 
disturbance of function in the other. At times, when 
changes are minute, the ophthalmoscope fails to 
definitely locate the site of disease. Perimetry there- 
fore may be of particular value in such instances. 

Perimetrically, there are two general symptoms 
which especially aid us in differentiating between 
primary disease of the choroid and of the retina. 



DISEASES OF THE INTRA-OCULAR VISUAL TRACT 103 

Shrinkage or loss of the blue field, out of porportion 
to the red and green, is characteristic of choroidal 
disturbance and disturbance of the rod and cone 
layers of the retina. Contraction of red and green, 
with fairly normal blue and form fields, on the other 
hand, is characteristic of changes in the inner layers 
of the retina and the ganglionic axis-cylinders which 
form the optic nerve. The behavior, therefore, of 
the blue, red and green fields may be the key to the 
differentiation between disease of the choroid and 
retina, when ophthalmoscopic symptoms are doubtful. 

A second broad perimetric difference between disease 
of the choroid and the outer layers of the retina, and 
disease of the ganglionic and nerve fiber layers of the 
retina, is in the character of the scotoma when present, 
especially in the macular region. Lesions of the choroid 
and rod and cone layer may be accompanied by a 
positive scotoma, or a blind area of which the patient is 
conscious. On the other hand, disease primarily in the 
inner neuron, that is, in the ganglionic cells and their 
axis-cylinders, is accompanied by a scotoma which, as 
a rule, is negative in character, a blind area of which 
the patient is not conscious. With this broad differ- 
entiation in mind, one may at times determine with 
precision the primary site of disease in the eye, even 
though the ophthalmoscopic evidence may be negative. 

Clinically, one observes at times in choroidal disease 
a contraction for red and green equal to, or greater 
than, that for blue, and a negative scotoma instead 
of a positive one. When these phenomena are present, 
it is probable that the inner neuron of the retina has 
become involved as well as the outer neuron and the 
choroid. 

Notwithstanding the usual secondary involvement 
of the retina in disease of the choroid, one finds distinct 
types of disease in which only one of these elements 



104 SPECIAL PATHOLOGY OF FIELDS 

is involved, or in which the symptoms of one so over- 
mask the secondary involvement of the other as to 
obscure its presence. 

Choroiditis. — In all types of choroiditis, as a rule, 
perimetric deviations will be found to correspond to the 
pathologic changes observable with the ophthalmoscope. 
Occasionally, in recent choroiditis, with only moderate 
absorption of retinal pigment, the ophthalmoscope may 
fail to reveal the disease. In such areas, a qualita- 
tive disturbance of the blue field may be made out 
by perimetric studies. Any part of the choroid may 
be involved. The characteristic perimetric evidence, 
therefore, of choroiditis is multiple scotomata dis- 
tributed irregularly over the field, usually positive, 
although sometimes negative in character — relative in 
the early history of the case, and absolute as the dis- 
ease progresses. In the syphilitic forms of the disease, 
a coalescence of the blind areas gradually brings 
about types of ring scotomata. In the regressive 
stage of this form of choroiditis, perimetric symp- 
toms appear in reverse order. As absorption takes 
place, a gradual shrinkage of the blind areas breaks up 
the ring formation, healthy choroid again " breaking 
through." Areas which were absolute scotomata now 
become relative, and either finally disappear, or remain 
blind to one or more colors and become indistinct in 
character. Perimetry therefore is of inestimable value 
in prognosis, both in the progressive and regressive 
stages of luetic choroiditis. 

Contraction of the peripheral field for form and 
colors is rarely observed in choroiditis, but when 
present it is an indication that the retina — and par- 
ticularly the axis-cylinders and the inner neuron of the 
retina — have become involved. This is observed in 
so-called choroiditic atrophy of the nerve or optic 
atrophy secondary to choroiditis. That marked dis- 



DISEASES OF THE INTRA-OCULAR VISUAL TRACT 105 

turbance in function may occur in choroiditis with- 
out ophthalmoscopic evidence is illustrated in a case 




Fig. 44.— December 9, 1913. Form Fig. 45.— December 20, 1913. Blind 

field contracted, blind spot enlarged. spot and ring scotoma shrinking under 
Absolute ring scotoma. antisyphilitic medication. Ring sco- 

toma absolute. 




Fig. 46.— December 31, 1913. 
Form field almost normal. Normal 
blind spot slightly enlarged. Minute 
area of the ring scotoma left, still 
absolute. 

Figs. 44-47. 



Fig. 47. — January 6, 1914. Form 
and color fields almost normal . Blind 
spot of Mariotte about normal. 
Small relative scotoma — the remains 
of the ring scotoma. 

Ring scotoma and syphilitic chorioretinitis. (Case of 
Dr. Wendell Reber.) 



of partial ring scotoma represented in Figs. 44 to 47. 
This case occurred in the practice of Dr. Wendell 



106 SPECIAL PATHOLOGY OF FIELDS 

Reber. The patient complained of a defect around 
central vision of the right eye. The ophthalmoscope 
did not show any variation from the normal. A peri- 
metric study, however, showed a positive and an 
absolute scotoma, horseshoe in shape, surrounding the 
macular region. Under salvarsan treatment the patient 
recovered completely. In this case the nutrition of the 
neuro-epithelium of the retina was disturbed by the 
syphilitic process. 

In all forms of choroiditis, perimetric studies furnish 
abundant justification for the time and labor spent. 
Not only is it an aid to diagnosis, but it furnishes the 
only dependable data upon which a prognosis can be 
made. Lues and tuberculosis are the acknowledged 
etiologic factors in a large portion of choroidal dis- 
eases, and when due to the former, improvement may 
be looked for under suitable treatment. During the 
regressive stage, therefore, the progress of the case can 
be determined more accurately and minutely than it is 
possible to determine by means of the ophthalmoscope. 

Idiopathic Nyctalopia. — Idiopathic nyctalopia, 
improperly called hemeralopia, is a condition in the 
production of which both choroid and retina have a 
share. Night-blindness is a symptom of retinitis 
pigmentosa, but the idiopathic variety is entirely 
functional in character and the eye-ground remains 
normal. It is characterized by anesthesia of the 
retina, loss of adaptation and diminution in central 
and peripheral qualitative and quantitative color sense. 
Pathologically, two factors probably are operative 
in its production — exposure to strong light and a 
condition of malnutrition. It occurs especially in 
soldiers' and sailors' barracks, in overcrowded orphan- 
ages, and in schools for children, and, as claimed by 
some, it is observed in Russia during the Lenten 
season. 



DISEASES OF THE INTRA-OCULAR VISUAL TRACT 107 

A study of these cases perimetrically shows espe- 
cially a quantitative loss of color sense, particularly 
for blue by daylight, but to greater extent in sub- 
dued light; contraction of form and color fields, 
increasing with twilight — and occasional shrinkage 
of the form field in good daylight. In all these 
variations from the normal, predominant symptoms 
are marked contraction of the blue field in good light, 
increasing under diminished light, and contraction to 
a less extent of the red and green in twilight. What- 
ever bearing exposure to excessive light may have on 
these cases, the dominating etiologic factor is that of 
malnutrition. The choroidal circulation is at fault, 
and the retinal anesthesia and loss of adaptation are 
the result of an altered blood supply to the neuro- 
epithelial layer of the retina. Constructive treatment, 
in the form of suitable food and fresh air, effects a cure. 

Idiopathic Hemeralopia. — Idiopathic hemeralopia, 
or day-blindness, is not accompanied by any alteration 
in the field. When it is a symptom of organic optic 
nerve disease, the perimetric findings are those of the 
disease of which it is a symptom. 

Retinitis. — Inflammation of the retina from any 
cause is primarily an inflammation of the ganglionic 
retinal area together with the axis-cylinders which go 
to form the optic nerve. It therefore is a disease of 
nerve elements proper. Disease of the retina differs 
from disease of the choroid because : ( i ) of the difference 
in the plan of nourishment; (2) in the fact that the 
nerve fiber layer consists of fibers of varying lengths — 
all, however, tending to converge toward the papilla 
where they are united into one bundle and become the 
optic nerve proper. Peripheral parts of the temporal 
retina are not only farther removed from the nerve 
head, the nerve head fibers passing to the optic nerve 
by a greater detour, but the blood supply from the 



108 SPECIAL PATHOLOGY OF FIELDS 

branches of the arteria centralis retinae is scantier 
and must pass by a longer route. Instead, therefore, 
of focal disease as usually observed in the choroid, 
inflammation of the retina, while at times focal in 
character, usually becomes diffused, or at least indi- 
rectly affects the peripheral retina. 

In addition to the various types of scotomata 
observed, a second symptom in perimetric study is 
added, namely, contraction of form and color fields. 
Reduction in the blue field usually is commensurate 
with that for form, but red and green suffer usually 
to a greater extent. In diffuse retinitis, therefore, 
one of the earliest symptoms is narrowing of the form 
field. On the other hand, the retinitis with a focus of 
greatest intensity in the central or intermediate zone 
may show a contraction for red and green out of 
proportion to that for form, especially when the 
examination is made in subdued light. Like idiopathic 
nyctalopia, a narrowing of the red and green field 
in subdued light may be an early sign of retinitis 
when both form and color fields are normal in good 
light. After retinitis becomes well established, the 
contraction of the green, red, blue and form fields 
may be proportionately equal, or areas of greater 
intensity may cause red and green to disappear before 
form has shown a great degree of contraction. 

Scotomata, when present, as a rule are negative in 
character. A relative scotoma, as the disease progresses, 
becomes absolute, and scotomatous areas are enlarged 
both peripherally and centrally. Ring scotomata may 
make their appearance, especially when retinitis is 
central or peripapillary, as the case may be. Ring 
scotomata, however, are not so frequently observed 
as in disease of the choroid. On the other hand, 
central scotomata are not unusual occurrences, as the 
macular region is frequently the seat of focal disease. 



DISEASES OF THE INTRA-OCULAR VISUAL TRACT 109 

In the regressive stage, absolute scotomata become 
relative, and the central and peripheral zones show 
evidence of improvement. First, green, which may have 




Fig. 48. — Ring scotoma due to peripapillary retinitis. 

been lost even in the macular region, may now reappear 
and the red field becomes enlarged. The peripheral 




Fig. 49. — Central chorioretinitis. Enlarged blind spot of Mariotte. Form 
fields normal. Green field totally lost. 

parts of the retina are the last to recover, and com- 
plete restoration of function can rarely be looked for 
in this part of the retina. The form field, as a rule, 



110 



SPECIAL PATHOLOGY OF FIELDS 



will remain permanently contracted. In Fig. 50 are 
recorded the fields of a severe case of luetic chorio- 
retinitis with fairly good recovery. Color fields are 
approximately normal. The form field in the left eye 
shows the greatest amount of contraction. Central 
vision is good in both eyes. 

Forms of retinitis which require special study are 
luetic, nephritic, diabetic, leukemic, retinitis pig- 
mentosa, solar and electric retinitis. 

Syphilitic Retinitis. — This infection is carried by 
the blood stream and therefore advances along the 




Fig. 50. — Luetic chorioretinitis. Recovery. 



bloodvessel supply. Foci of disease of greater intensity 
are apt to be present along with diffuse retinitis. 
The choroid is likewise invaded, and the symptoms, 
as a rule, form a composite picture of chorioretinal 
disturbance. Moreover, the optic nerve itself usually 
shares in the inflammation. In these cases symptoms 
of inflammation of the inner neuron may predominate. 
Contraction of form and color fields is in evidence early. 
In the course of a few days central vision may be 
reduced to light perception. If the process is central, 
various types of scotomata develop. Indistinct scoto- 
mata are frequently noted, and as the disease pro- 



DISEASES OF THE INTRA-OCULAR VISUAL TRACT 111 

gresses, relative, and finally absolute scotomata appear. 
At times they are central, in other cases multiple, 
with formation of an irregular ring scotoma. They are 
usually negative in character because of the greater 
involvement of the nerve elements, but the positive 
blind area is also seen. In fact, no type of retinitis 
is more varied in its perimetric symptomatology than 
that of lues. As prognosis is more favorable in this 
type of retinal inflammation that in any other form 
of retinitis, perimetric studies are particularly varied 
and valuable in the regressive stage of the disease. 
In fact, in so many instances the onset is so rapid 
that field studies are not of much value in the early 
stages of disease. Recovery is rarely complete, espe- 
cially in the extreme peripheral parts of the retina; and 
when carefully studied, indistinct types of scotomata 
may be found, even in the central zone. 

Nephritic Retinitis. — Nephritic retinitis, inaptly 
called by the older writers "albuminuric retinitis," 
is a form of retinal disease in which arterial hyperten- 
sion is the chief etiologic factor. It varies in degree 
from a mild, localized or diffused edema of the retina, 
to a neuroretinitis at times hemorrhagic in type, and 
a papilledema which to all appearances resembles 
choked disc of brain tumor. The so-called albuminuric 
retinitis is only one of the types of eye-ground changes 
observed in chronic interstitial nephritis. In the 
early stages a hazy retina may be observed together 
with a loss of light streaks on the retinal vessels. 
Occasionally, even at this early stage, small areas of 
marked edema may be observed, especially in the 
macular region. Perimetrically, it is characteristic 
of this condition to find at the onset of eye complica- 
tions, in this mild form, a beginning contraction of 
both form and color fields. The edematous areas in 
the macular region are recognized by the patient as 



112 



SPECIAL PATHOLOGY OF FIELDS 



indistinct scotomata, often positive in character. If 
hemorrhages appear cf sufficient size and density, rela- 
tive and absolute scotomata are found to correspond 
to the hemorrhagic areas. More often, hemorrhages, 
even of dense character, are apt to produce indistinct 
scotomata. The so-called albuminuric retinitis stage 
is characterized by marked contraction for form and 
colors, and scotomatous areas which coincide with the 
atrophic areas, which have given this form of retinitis 
its name. The enlargement of the normal blind spot 
of Mariotte marks the beginning of a swelling of the 




Fig. 51. — A typical field of chronic interstitial nephritis. Blood-pressure 

200 mm. Hg. 



nerve head, and irregular scotomata in the central 
zone are the evidence of changes in the nerve head 
and retina incident to the choked disc, namely, hemor- 
rhage, atrophy, and detachment of the retina. 

Perimetric studies in nephritis of pregnancy differ 
very little from those described for chronic interstitial 
nephritis. The toxic element is probably more in 
evidence than that of hypertension. The perimetric 
findings therefore are the result more directly of dis- 
turbed nutrition than of edema, and contraction of 
form and color fields is quite common. When eye 



DISEASES OF THE INTRA-OCULAR VISUAL TRACT 113 

changes are marked, the perimetric changes become 
those which are noted in chronic interstitial nephritis. 




Fig. 52. — Chronic interstitial nephritis. Indistinct central scotoma due to 
edema and partial detachment. Scotomata positive. 

However, in this form of nephritis recovery may 
become complete and fields may become relatively 
normal. 




Fig. 53. — Neuroretinitis in the eighth month of pregnancy. Absolute 
enlargement of the normal blind spot surrounded by a relative scotoma for 
red. Recovery. (Casex>f Dr. Reber.) 



The perimetric characteristics of nephritis retinitis, 

therefore, are: (i) contraction of form and color 

fields, even in the early stages of the disease; (2) 
8 



114 SPECIAL PATHOLOGY OF FIELDS 

indistinct scotomata which later may become relative 
or absolute. These scotomata may occur in any part 
of the field, but most characteristically develop in 
and about the macula; (3) enlargement of Mariotte's 
blind spot. 

Diabetic Retinitis. — In diabetic retinitis, perimetric 
changes similar to those of chronic Bright's disease 
are observed, but milder in character. The contraction 
of form and color fields is present, but not to so great 
an extent. As the atrophic areas are usually minute 
and scattered, scotomatous areas are not so frequently 
observed. They are, however, present in some cases, 
and usually are situated in the macular region. As 
arterial hypertension is not so great, hemorrhagic 
retinitis is less frequently observed, and when present 
the hemorrhagic areas are smaller and less apt to give 
rise to scotomata of sufficient size to be recognized. 
It is well to remember, however, that chronic diabetes, 
as a rule, may eventually be accompanied by chronic 
interstitial nephritis, and the perimetric findings may 
become as marked as in a case of chronic Bright's 
disease. 

Leukemic Retinitis. — In leukemia, pernicious anemia, 
and other blood dyscrasiae, a form of retinitis is observed 
which is characterized by large and massive hemor- 
rhages. Occasionally an optic neuritis may be present. 
The process as a rule is a rapid one, and therefore the 
eye symptoms are due largely to hemorrhagic retinitis. 
Positive, indistinct, irregular, scotomatous areas are 
observed by the patient, and the perimetric findings 
correspond to the blood areas observed. If neuro- 
retinitis is present and the disease is prolonged, con- 
traction of form and color fields may be observed. 
Vision, however, may be so rapidly lost in this type 
of disease that perimetric studies are not of great 
value. 



DISEASES OF THE INTRA-OCULAR VISUAL TRACT 115 

Hodgkin's Disease. — The author had the opportunity 
of studying a neuroretinitis in a well-marked case of 
Hodgkin's disease. The eye-ground resembled the 
eye-ground frequently observed in advanced tubercu- 
losis, namely, a blurred disc, the retina hazy through- 
out, engorgement of the retinal veins, some tortuosity 
of the arteries, and total absence of the light streaks 
on vessels. Fields in this case show a contraction 
for form and color. 

Solar and Electric Retinitis. — Exposure of an unpro- 
tected eye to a solar eclipse sometimes produces a 




Fig. 54. — Fields in a case of Hodgkin's disease. 



form of retinitis which is characterized by a positive 
central or paracentral scotoma which may be temporary 
in character, but more often permanent. In the 
zone immediately surrounding this scotoma, marked 
changes in color fields may be noted which take the 
form of indistinct, relative or absolute scotomata. 
These scotomata may disappear, or may remain 
permanently. Contraction of the form field is also 
observed if the exposure to the sun's rays has been 
prolonged. A similar condition is observed in sudden 
exposure to a strong electric-light explosion. Marked 
atrophy of the retina and of the optic nerve may 



116 



SPECIAL PATHOLOGY OF FIELDS 



result, and the damage frequently is permanent. Posi- 
tive central scotomata, with marked disturbance 
for colors over large central areas, and contraction 
of form and color fields, are the usual evidences on the 
perimeter. 

Jess 1 reports 26 cases of ring scotomata out of a total 
of 36 cases studied. In most instances the ring was 
incomplete, varied from 10 to 25 degrees in width, and 




Fig. 55. — Entoptic study of a ring scotoma due to looking into a furnace fire. 
(Case of Dr. J. Claiborne.) (Annals of Ophthalmology.) 

usually was found between the 20th and 50th degrees. 
Speleers, 2 found a similar condition in 6 cases out of 
13 studied, and in 11 cases he noted an enlargement of 
the blind spot of Mariotte. 

It is difficult to explain the origin of ring scotoma 
in solar retinitis. In the light of our present knowledge, 
however, the injury may be regarded as thermic. 



1 Arch. f. Augenh., lxxiv, 78. 

2 Klin. Monatsbl. f. Augenh., November, 1912, p. 636. 



DISEASES OF THE INTRA-OCULAR VISUAL TRACT 117 

In snow-blindness, the ultra-violet rays play the 
important role. 

An unusual case of ring scotoma has recently been 
reported by Dr. J. Herbert Claiborne in the Annals 



90° 




Fig. 56. — Perimetric study of Dr. Claiborne's case of ring scotoma. 
(Annals of Ophthalmology.) 

of Ophthalmology, January, 19 15. The scotoma was 
due to looking into a furnace fire for a long period. 
Fig. 55 represents the drawing of the scotoma by the 
patient, by entoptic study, and Fig. 56 the field of the 
patient taken on the perimeter. 



118 SPECIAL PATHOLOGY OF FIELDS 

Retinitis Pigmentosa. — Retinitis pigmentosa is an 
atrophic or sclerosing process which involves the choroid 
and retina. By some it is believed the choroid is the 
first to suffer; whereas, others believe the sclerosis 
develops in the choroid and retina about the same 
time. It is, as a rule, hereditary, recurring frequently 
in several members of the family, and in a large per- 
centage of the cases in children of consanguineous 
marriages. Clinically, it is characterized by an early 
deposit of pigment of peculiar arrangement about the 
equator of the eyeball, by atrophy of the optic nerve 
with fairly distinct nerve head, a marked contraction 
of both retinal arteries and veins, and a visible cho- 
roidal circulation which becomes more plainly visible 
as absorption of pigment of the neuro-epithelial layer 
progresses. The symptom of which the patient com- 
plains is gradual loss of vision, which is especially 
marked in twilight. Patients whose orientation in 
daylight is good find it difficult to grope their way 
in the dark. This night-blindness, or nyctalopia, is 
present in most cases, but occasionally may be found 
absent. 

Perimetrically, the characteristic symptoms are: 
(i) a progressive and rapid contraction of the form 
field, sometimes irregular, but usually concentric; 
(2) preservation of central vision for form and colors 
long after peripheral vision has become extensively 
lost; (3) ring scotomata, in the earliest stages of 
disease; (4) the absence of central defects until the 
progressive loss of the form field encroaches upon 
central vision. Most of those who have made careful 
studies of the condition agree that progressive con- 
traction of the form field is the earliest and most 
characteristic perimetric finding. Kollner, however, 
claims the broad ring scotoma is the earliest perimetric 
symptom. Most investigators believe the choroid 



DISEASES OF THE IXTRA-OCULAR VISUAL TRACT 119 

suffers first, and the observations of Kollner would 
tend to confirm this view. As a matter of fact, how- 
ever, few cases are studied sufficiently early to confirm 
Kollner's observation, but clinically, a contracted 




s %\ 




Fig. 57. — Retinitis pigmentosa. 

form field is usually the first perimetric symptom to 
be noted. In many cases, the contraction takes place 
irregularly. It is interesting to note that the red 





Fig. 58. — Retinitis pigmentosa. (Case of Dr. Wendell Reber.) 

field may extend well up to the limits of the form field. 
A larger number of cases show, on the other hand, 
the concentric contraction of form and color fields, 
especially when the contraction is marked, as in Fig. 58. 



120 SPECIAL PATHOLOGY OF FIELDS 

The above field illustrates well the second character- 
istic of retinitis pigmentosa, namely, a preservation of 
central vision out of proportion to the contraction of 
the form field. Exceptions to this symptom are 
occasionally noted when the process begins in the 
central zone rather than in the equator of the eyeball. 
Nearly all of the fields taken in this disease exhibit 
color fields which are as extensive, or nearly so, as the 
form field. In Shoemaker's study of 17 cases he was 
able to demonstrate color sensibility in the macula 
in most of his cases with an object as small as 2 mm. 
in diameter. The macular sensibility in most instances 
is preserved until late, not only for colors, but central 
vision remains fair even when orientation becomes 
difficult because of contracted fields. Numerous 
instances are recorded in which the patient was able 
to pick out individual letters in print when orientation 
was completely gone. 

In Shoemaker's 17 cases, he was unable to find an 
instance of ring scotoma. He concludes, therefore, 
that if present at all, it is a rather rare phenomenon. 
Theoretically, if our suspicion of early choroidal in- 
volvement is correct, the ring scotoma should be of 
frequent occurrence. Practically, however, it is infre- 
quently observed, and this notwithstanding the 
reference made to it by nearly every writer on the 
subject. Possibly this discrepancy can be explained 
by the rather late studies which are usually made in 
this disease. 

Finally, it is generally conceded that central vision 
is intact, or at least present, late in the disease; central 
scotomata are observed only in those anomalous cases 
in which the sclerosing process affects primarily the 
macular region and the peripheral involvement becomes 
secondary. Cases of this type appear in literature. 
Central vision, as a rule, finally disappears and the 



DISEASES OF THE INTRA-OCULAR VISUAL TRACT 121 

patient becomes blind. A few cases, however, show 
a tendency to arrest of the process after the fields have 
become markedly contracted, and in a few instances 
fields have been preserved even in late adult life. 

The luetic origin of a few cases has been conceded 
by some, but denied by others. In Fig. 59 is recorded 
a field of retinitis pigmentosa in which I believe lues 
is the cause. The eye-ground has the appearance of the 
typical retinitis pigmentosa, hereditary in origin. In 
addition, however, the nerve head is quite indistinct, 
there is a perivasculitis present, and there are fine 




Fig. 59. — Retinitis pigmentosa of luetic origin. (Patient in service of 

Dr. Reber.) 



opacities in the posterior part of the vitreous body. 
Furthermore, his sight began to trouble him at about 
forty years of age. He admitted the history of a 
chancre and he had a positive Wassermann. The case, 
I believe, is one of luetic retinitis pigmentosa. 

Detachment of the Retina. — Perimetric studies in 
retinal detachment are of most value in the predetach- 
ment period and: in the stage of recovery, if reattach- 
ment takes place. In a retinal detachment which is 
plainly visible by the ophthalmoscope and by the 
patient, a field defect for form and color will be found 



122 SPECIAL PATHOLOGY OF FIELDS 

corresponding to the detached area, recognized by the 
patient as a positive scotoma and by the physician as 
a gray elevated area in which light reflex is absent. 
When complete, the detachment gives rise to an abso- 
lute scotoma. In its earlier stages, however, when 
the patient is conscious only of the cloudy area in his 
field, an indistinct scotomatous area will be detected 
in which possibly only qualitative color changes may 
be observed. Blue-blindness, or at least a qualitative 
change in blue, is one of the earliest symptoms at this 
stage of the process. After the retina has become 
separated and an absolute scotoma appears, there 
will be found an indistinct scotomatous area surround- 
ing the absolute scotoma in which these qualitative 
changes will appear. 

In disseminated choroiditis, high myopia, retinal 
edema of chronic interstitial nephritis, or other condi- 
tions in which retinal detachment may appear, per- 
imetric studies are of great value. Lohmann has called 
attention to green vision of patients for weeks before 
detachment appeared, the same symptom being present 
in one case a year after reattachment. He quotes 
Kollner's observation, especially in one patient who 
saw blue hyacinths as green in the affected eye. Other 
patients will see green spots in their visual field. 
Blue-yellow-blindness may therefore be regarded as 
an early symptom of retinal detachment. Blue may 
appear as green or black, and yellow as white. 

When reattachment takes place, as in the milder 
forms of the disease, the form field may again be 
restored. Qualitative changes in color, however, are 
more or less permanent, even in mild cases. In 
Fig. 60 is represented a form of retinal detachment 
which occurred in chronic interstitial nephritis. Sub- 
jectively, the patient complained of an unevenness of 
the floor, and a sensation of wet spots on the floor and 



DISEASES OF THE INTRA-OCULAR VISUAL TRACT 123 

street. Perimetrically, he showed an indistinct scotoma 
for form and marked confusion for colors in the macular 
region. A white edematous area was recognized in the 
macula by the ophthalmoscope, in addition to other 
phenomena of chronic Bright 's. Recovery was good, 
but qualitative color changes remained in the region of 
the detachment. 

As to the location of the scotomatous areas. Detach- 
ment may occur in any part of the retina. Its location 
will be determined by the cause of the detachment. 
Its tendency, however, is downward, unless caused 




Fig. 60. — Partial detachment of retina in a case of chronic interstitial nephritis. 



by a neoplasm, when the detachment will be in the 
direction of the growth. If the detached retina is in 
the upper part of the eye, the defect will appear in the 
lower part of the field, and vice versa. The line of 
development will be down, the upper part often re- 
attaching itself as detachment increases downward. 
In malignant forms of detachment, when the vitreous 
body shrinks, the condition grows progressively worse 
until the retina is attached only at the ora serrata and 
the posterior pole of the eye, and vision becomes 
entirely lost. It is possible in many instances to follow 
a detachment when it is advancing by means of the 



124 



SPECIAL PATHOLOGY OF FIELDS 



ophthalmoscope, and the patient, if intelligent, can 
note the progress of the disease entoptically. The 
perimeter, however, gives one more accurate knowl- 
edge, and it is especially of value in determining the 
probable arrest of the process. 

Commotio Retince. — The vulnerability of the macula 
is observed in commotio retinae. In direct blows on 
the eyeball, injury is liable to show itself at a point 
directly opposite the point of contact, namely, at the 
macula (contracoup). The patient complains of an 
area of cloudiness which may center in the macula or 




Fig. 61. — Retinal detachment. (Reber.) 

may surround central vision. The usual ophthalmo- 
scopic symptoms will be observed in proportion to 
the severity of the injury. A positive scotoma may be 
observed centrally, or, more frequently, a ring scotoma 
may be formed. Lohmann has endeavored to explain 
this ring scotoma by the firm attachment of the tunics 
of the eye to the optic nerve, thereby preventing the 
macular region from being wrenched from its attach- 
ments. The force of the blow is distributed around 
the papillomacular region. The explanation appeals 
to one as being entirely rational and plausible, and it 
will explain the formation of a ring scotoma in this 



DISEASES OF THE INTRA-OCULAR VISUAL TRACT 125 

disease when visual acuity remains normal. It is 
reasonable to expect a central defect in direct blows 



. z 




Fig. 62. — Injury of optic nerve from a blow on the eyeball. Enlarged blind 

spot of Mariotte. 

upon the eyeball. The greater activity of the macular 
region is made possible partly by the greater activity 
of the choroid underlying it. Injury to the choroidal 




Fig. 63. — Commotio retinae. Enlarged blind spot of Mariotte. Indistinct 
paracentral scotoma. Form and color fields much contracted. 

circulation, therefore, is apt to be followed by retinal 
changes. Notwithstanding the possible influence of 



126 SPECIAL PATHOLOGY OF FIELDS 

the firm attachment to the optic nerve, visual acuity 
often suffers. The relative or absolute character of 
the scotoma, whether central or ring, and the extent 
of the blind area, will depend much more upon the 
severity of the blow. Recovery may be good and 
complete, but in severe forms there may be not only 
permanent central defects, but the peripheral area of 
the retina may show disturbance in the contraction 
of form and color fields (see Fig. 63). 

Traumatic Anesthesia of the Retina. — Traumatic anes- 
thesia of the retina is the name given by Leber to 
a group of symptoms following injury to the globe 
without discoverable ophthalmoscopic changes. It 
forms a symptom group which really belongs under the 
heading of Commotio Retinae or Traumatic Retinal 
Edema. Clinically, it differs only from the latter in the 
absence of visible signs other than disturbed central 
vision. The perimetric findings agree with those which 
have just been described under Commotio Retinae. 
The injury in these cases seems to cause a rather 
diffuse disturbance of the retina, which may result 
in central and paracentral defects and considerable 
contraction of the form field. Perimetric changes 
may remain permanently, or they may disappear in 
a few days. 

Traumatic Hole in the Macula. — In this same group 
one might include this rather rare phenomenon which 
may follow a contusion of the eyeball. A depression 
may be observed in the macula of a deep red color 
with clear-cut edges. This may be the only evidence 
of injury, in which case a small scotoma will be found 
centrally or paracentrally situated, or there may be 

Rupture of the Choroid or Retina. — Rupture of the 
choroid or retina may be found associated with it. 
One or more white lines may be found radiating from 
the macular hole, with or without hemorrhages along 



DISEASES OF THE INTRA-OCULAR VISUAL TRACT 127 

their course. A break in the choroidal circulation will 
be followed by retinal changes in the same area, 
and permanent scotomatous areas will be found to 
correspond to the atrophy of the choroid and retina 
which follows. The choroid may alone be found 
ruptured, but retinal atrophy must necessarily follow 
because of disturbance of its nutrition. In the more 
aggravated cases, retinal detachment may be the final 
outcome, and corresponding perimetric symptoms will 
therefore be elicited. 

Embolism and Thrombosis of the Central Artery of 
the Retina. — Three types of occlusion of the central 
artery of the retina are observed: Embolism, throm- 
bosis, and occlusion by endarteritis proliferans. Clinic- 
ally, it is not always possible to differentiate between 
these types of occlusion, but the ultimate effect upon 
the retina is probably the same. Perimetric studies 
in these conditions are of little value in some cases, 
but of great value in others. The onset in embolism 
is so sudden that vision is lost throughout the retina 
suddenly and blindness is the result. The process in 
thrombosis and in endarteritis is more gradual, but 
also complete in many instances. More frequently 
one or more branches of the central artery are affected, 
and disturbances of vision therefore is only partial. 
The part of the retina supplied by the occluded vessels 
will show total absence of form and color fields, the 
balance of the field remaining intact. 

Fig. 64 is the field of a patient who, at eighteen years 
of age, suffered from thrombosis of the inferior branch 
of the central artery of the retina. The inferior retinal 
vessels are reduced one-half, the inferior part of the disc 
is atrophic, and the lower half of the retina shows the 
usual atrophic pallor. Central vision was not disturbed. 
It is now 20/12, ten years after the thrombosis occurred. 
Even in the seeing half of the field one notes the 



128 



SPECIAL PATHOLOGY OF FIELDS 



peripheral part of the retina has suffered. The colors 
have also undergone a moderate degree of contraction. 




Fig. 64. — Thrombosis of inferior branch of central artery of retina of twelve 

years' standing. 

Along the upper border of the field, color fields coincide 
with that for form. The presence of cilioretinal vessels, 
which occur in about 16 per cent., sometimes saves 
central vision. A slit-like field, running horizontally, 




V.-jku 



Fig. 65. — Embolism of central artery of retina. Cilioretinal vessels intact. 

(Reber.) 

will be preserved in the macular region, even though 
the central artery is completely occluded, if the cilio- 



DISEASES OF THE INTRA-OCULAR VISUAL TRACT 129 

retinal artery is present. The extent of the preserved 
field will depend upon the size and the extent of the 
distribution of the cilioretinal vessels. In exceptional 
instances these vessels are unusually large and have 
a rather wide distribution. Under these circumstances, 
a considerable part of the perimacular field will be 
preserved. 

If blindness from occlusion of the central artery of 
the retina is complete and remains so for several days, 
even partial recovery is not likely to occur. In rare 
instances, treatment is of some avail and sight may be 
recovered. The completeness and duration of the 
occlusion will determine the extent of the recovery. 
In arteriosclerosis, angiospasm may be a cause of this 
phenomenon, and both clinical and perimetric signs 
of arteriosclerosis will be present. Recurrent attacks 
of angiospasm, therefore, with contraction of form and 
color fields which persists between the spasmodic 
seizures, is a bad omen. Such attacks should be 
looked upon as danger signs of great moment. 

If recovery from occlusion of the central artery or 
its branches takes place, restoration of the retinal func- 
tion may be complete, or the field may be disturbed in 
whole or a part. The peripheral parts of the retina 
may show contraction of form and color fields and 
scotomatous areas may be found. Such changes will 
be similar to those found in disease of the ganglionic 
and axis-cylinder layers — the red-green changes being 
most marked and persistent. 

Thrombosis of Retinal Veins. — Thrombosis of the 

retinal veins, clinically, presents a picture which differs 

markedly from that of occlusion of the central artery. 

Insofar as the ultimate outcome is concerned, however, 

it differs but little. It is a destructive process, and 

blindness as a rule is the sequel. The rapidly developing 

edema of the nerve head and retina, associated with 
9 



130 SPECIAL PATHOLOGY OF FIELDS 

large hemorrhages and exudate, quickly destroys the 
eyesight. Perimetric studies are not essential in 
diagnosis, and of little or no value in prognosis. Prog- 
nosis is usually bad. Thrombosis of a branch gives 
rise to an indistinct relative or absolute scotomatous 
area, the extent of which will depend upon the location 
of the thrombosis. 

Fields in Retinal Anemia from Hemorrhage in Remote 
Parts of the Body. — These hemorrhages may occur 
from the stomach, lungs, uterus, venesection, etc. 
The blindness and defects in visual fields are now 
recognized as the result of degeneration of the ganglionic 
and nerve-fiber layer of the retina, due to improper 
nutrition. Blindness may follow a single hemorrhage, 
or repeated hemorrhages. It may develop during the 
course of the hemorrhage, or be complete only after a 
period of several months. The prognosis is not favor- 
able, as high as 50 per cent, remaining unimproved, 
while a small number are improved, and possibly 10 
to 15 per cent, recover completely. Perimetric findings 
vary greatly. There may be concentric contraction 
for form and color, this contraction continuing to 
the extent of 15 degrees, or remaining in status quo, 
or blindness may supervene. In other instances 
sector-like defects or scotomatous areas — relative or 
absolute, central or paracentral in character — may 
develop. In color loss, the red-green fields are more 
affected than the blue-yellow, although in some 
instances all suffer alike. When recovery takes place, 
the color and form fields are restored inversely to the 
order in which defects appeared. 

Coloboma of Choroid and Retina. — Coloboma of the 
choroid and retina is an associated condition, and 
as a rule is bilateral. As the retina is either totally 
absent, or in an atrophic state, a scotomatous field 
defect is found corresponding to the area observed 



DISEASES OF THE IXTRA-OCULAR VISUAL TRACT 131 

with the ophthalmoscope. The scotoma, however, 
as a rule is relatively smaller than the coloboma, and 
in the periphery of the scotoma may be found an 
indistinct scotomatous area. The rod and cone 
elements are present in this area, but not so active as 
in other parts of the retina, and a qualitative and 
quantitative loss of light and color sense can be made 
out. The scotoma proper may be relative or abso- 
lute, but usually is negative in character. Instead of 
total absence of light sense in the colobomatous area, 
modified light sense may be preserved, as demonstrated 
by Schmidt-Rimpler and others. The presence of 
color sense has also been demonstrated in colobomatous 
areas. This would argue for the preservation of the 
retina in a modified form in some colobomata. As 
most colobomata extend close to the disc, the field 
defect observed may be continuous with the enlargemet 
of the normal blind spot of Mariotte. This is especially 
true when the coloboma includes the entrance of the 
optic nerve. 

Coloboma of the Optic Nerve. — Coloboma of the optic 
nerve is rarely found as a distinct and separate condition, 
but usually is associated with coloboma of the choroid 
and retina. It does occur, however, occasionally — - 
not only in the form of Fuch's coloboma, but in a total 
coloboma of the optic nerve without much involvement 
of the choroid and retina in immediate juxtaposition. 
Coloboma, however, is a congenital defect, and it 
therefore is usually found associated with other con- 
genital anomalies. It not infrequently happens in 
this form of coloboma as in others, that we not only 
find a negative scotomata, relative or absolute, but 
other field defects as well. Peripheral changes are 
frequently observed. Concentric, or more frequently 
irregular, contraction of both form and color fields 
have been recorded. 



132 



SPECIAL PATHOLOGY OF FIELDS 



Coloboma of the Macula. — Coloboma of the macula 
occurs as an isolated condition, or a part of a more 
extensive colobomatous area. Under any condition of 
macular coloboma, a central scotoma will be found; 
and in those cases in which the coloboma is extensive, 
involving a large portion of the posterior part of the 
eye, fields may be found so defective as to be difficult 
to take. In Fig. 66 is recorded the field of a patient 
suffering from unilateral coloboma which includes the 
optic nerve and macula. In the center of the field 




Fig. 66. — Coloboma of optic nerve and posterior pole of eyeball. 



is an absolute scotoma which corresponds to the 
colobomatous area as observed by the ophthalmoscope. 
While useful peripheral vision is preserved, there 
is shrinkage of both form and color fields. 

Persistent Medullated Nerve Fibers.— Persistent 
medullated nerve fibers give rise to field defects directly 
in proportion to their number and extent. These 
medullated nerve fibers are usually found above and 
below and in the direction of the distribution of the 
nerve fibers. They are usually opaque, and therefore 
the perimetric defect observed is enlargement of the 



DISEASES OF THE INTRA-OCULAR VISUAL TRACT 133 

normal blind spot in an upward and downward direc- 
tion. As medullated nerve fibers are not found in any 
great number much beyond the disc, other field defects 
are rarely observed. 

Wounds of the Retina. — In wounds of the retina a 
varied perimetric picture will be found, as might be 
expected, the defects being influenced by the character 
and extent of the wound. The nerve fibers are dis- 
tributed radially from the optic disc to the periphery 
excepting in the macular region, where they become 
somewhat deflected from their course to supply the 
peripheral region beyond the macula. A punctured 
or incised wound of the sclera, choroid and retina, 
therefore, if made in the direction of the nerve fibers, 
may not produce other field defects than a small 
coloboma corresponding to the size and shape of the 
wound, providing the choroid and retina have not 
been loosened from their attachment. When, however, 
a wound is made through the sclera, at right angles 
to the radiations of the retinal nerve fibers, an atrophic 
area will eventually be found extending from the line 
of the wound to the extreme periphery of the ora 
serrata, more or less quadrangular in shape, as the 
retinal nerve fibers severed must necessarily undergo 
degeneration throughout the extent of their distribution 
from the site of the wound. It will rarely happen, 
however, that an incised wound of the sclera, choroid 
and retina can be made without more or less early and 
late detachment of the retina for some distance beyond 
the immediate neighborhood of the wound. A scotoma- 
tous area, therefore, may be found extending from a 
point in the field corresponding to the location of the 
wound in the retina to the extreme periphery — or 
what is more frequently the case, the defect may extend 
beyond the borders, as the extent of the detachment 
will determine. Perimetric findings may be out of 



134 SPECIAL PATHOLOGY OF FIELDS 

proportion to the apparent size and extent of the 
wound, and will depend upon the nature and degree 
of the trauma inflicted. 

DISEASES OF THE PAPILLA, OR INTRA-OCULAR 
PART OF THE OPTIC NERVE. 

Anatomically, the nerve head is distinguished from 
the nerve proper by the absence of medullated sheaths, 
and for convenience in discussion, this part of the 
optic nerve will be separated from disease of the optic 
nerve proper. In this group will be included choked 
disc and glaucoma. 

Choked Disc, Papillitis, or Papilledema. — 
Choked disc, papillitis or papilledema, is part of an 
inflammation of the optic nerve. So typical, however, 
is the ophthalmoscopic picture that it is regarded as a 
distinct clinical entity. The perimetric findings are 
as varied as the conditions which bring about the 
choked disc, and no perimetric symptom or symptom- 
complex may be regarded as pathognomonic of the 
condition. In some instances, at least in the early 
stages, no external evidence of the presence of choked 
disc may be found other than the ophthalmoscopic 
evidence, and perimetric changes may be absent. The 
extent and the stage of the papillitis will largely 
determine the perimetric findings. Enlargement of the 
normal blind spot, central scotoma relative or absolute, 
concentric contraction, or sector-like defects of form 
and color fields, qualitative and quantitative loss of 
color fields alone, inversion of color fields, and early 
loss of nasal field while the temporal field is yet intact, 
have all been observed in the various stages of papillitis. 
So varied is the etiology, and so intimately is choked 
disc associated with disease of different parts of the 
optic tract that it can only be discussed in a general 
way. 



DISEASES OF THE PAPILLA 135 

If we accept the mechanical theory as to the etiology, 
there may be a time in the development of papill- 
edema when only the distal, or intra-ocular end of 
the optic nerve is involved. An ascending neuritis 
will undoubtedly follow, and ascending or descending 
atrophy will eventually supervene. When, therefore, 
it exists as a separate entity, what may be regarded as 
rather characteristic of the condition is an enlargement 
of the normal blind spot. Instead of an absolute 
enlargement, an indistinct scotomatous area may be 
found surrounding a blind spot of normal size, in which 
both color and form can be determined but with 
uncertainty. If the swelling increases and persists, 
the more vulnerable papillomacular bundle of nerve 
fibers may lose their integrity, and a central relative, 
and later absolute, scotoma may appear. Union of 
the enlarged blind spot and the central scotoma will 
give rise to a pericentral scotoma. Active inflammation 
of the optic nerve, associated with choked disc, brings 
about peripheral changes in the field, a concentric 
contraction, or more often sector-like defects of both 
form and color fields. In fact, the presence of changes 
in the peripheral fields early in the history of the 
papillitis is evidence of optic-nerve involvement rather 
than that of the swollen disc. 

In the acute inflammatory stage, perimetric symp- 
toms directly referable to the swollen nerve head will 
be largely confined to the region of the normal blind 
spot and macula. Continued engorgement, however, is 
necessarily followed by atrophy on account of the con- 
tinued pressure under which the nerve fibers are held. 
Therefore, at the height of the choked disc, or in the 
regressive stage, peripheral form and color changes 
make their appearance. These changes consist in 
reversal of color fields, as pointed out by Cushing and 
others, in choked disc of brain tumor origin, con- 



136 SPECIAL PATHOLOGY OF FIELDS 

centric contraction and sector-like defects of form and 
color fields, and in rather rapid loss of the nasal fields — 
according to Gushing and Walker. 1 All these peri- 
metric findings have been confirmed by numerous 
investigators. They should, however, be recorded as 
the result, not so much of the papilledema per se, 
but as indicating damage to the other parts of the 
retina, and possibly also in part of psychic origin, as 
exemplified in reversal of the color fields. Whatever 
may be the direct cause of reversal of color fields 
as a symptom of brain tumor, one must not lose 
sight of the fact that hysteria is not infrequently an 
associated condition in patients suffering from brain 
tumor, and that the condition can be best explained 
on a psychologic basis. Reversal of color fields is 
typically observed in hysteria, and this form of peri- 
metric change should be looked upon as of psychic 
origin. Against the organic origin of this phenomenon 
is the fact that it has been observed in neoplasm of 
various parts of the brain. It is not peculiar to disease 
of any particular area. 

Contraction of form and color fields, whether con- 
centric or sector-like, is usually a late phenomenon 
and indicates nerve-fiber degeneration. Equally inter- 
esting is the rather rapid loss of the nasal field, or 
so-called nasal hemianopsia referred to by Cushing 
and Walker in the choked disc of brain tumor. The 
method of development of this phenomenon has been 
ingeniously explained by these authors as a pressing 
out of the chiasm by the distention of the third ventricle 
so as to press the sides of the chiasm against the carotid 
arteries even to the extent of an indentation of the 
chiasm. To this, in part, is attributed the symmetric 
disturbance of the nasal fields so often observed in 
brain tumor. If this theory is correct, it should be 

1 Archives of Ophthalmology, November, 1912. 



DISEASES OF THE PAPILLA 137 

equally true that a force sufficient to crowd the optic 
nerve against the carotid arteries would likewise bring 
about types of altitudinal hemianopsia in forcing the 
chiasm down upon its bony bed in the sphenoid. In 
overcrowding of the fibers in the optic nerve head, such 
as occurs in choked disc and glaucoma, the secondary 
atrophy which necessarily follows will make its appear- 
ance first in the nasal field because of the peculiar 
distribution and anatomic arrangement of the retinal 
nerve fibers. It has been pointed out elsewhere that 
because of the eccentric location of the disc and the 
direct route of the macular bundle of. nerve fibers, 
the temporal distribution of the optic nerve is accom- 
plished by a longer and more circuitous route than the 
direct radiations of the nasal retina. The temporal 
retina is therefore the first to suffer from secondary 
or pressure atrophy such as occurs in choked disc 
and in glaucoma. It is probable, therefore, that the 
so-called nasal hemianopsia which has been observed 
in brain tumor can be readily explained in this manner. 
Furthermore, the pathologic findings at our command 
tend to show that pressure from a distended third 
ventricle produces bitemporal hemianopsia rather 
than binasal. Siemerling 1 calls attention to a chiasm 
almost divided by a greatly distended third ventricle, 
thereby giving rise to bitemporal hemianopsia. A sim- 
ilar condition is observed in simple chronic glaucoma, 
a pathologic process which primarily is practically 
confined to the bulbar end of the optic nerve. It is 
reasonable, therefore, in the regressive stage of choked 
disc of brain tumor origin, in which the pathologic 
process as an end-result is the same as in glaucoma, 
i. e., a secondary atrophy, to account for the early 
shrinkage of the nasal field in the same manner as in 
glaucoma, rather than by the pressure of the carotid 

1 Archives fur Psychiatrie und Nervenkrankheiten, Band xx, Heft 1. 



138 SPECIAL PATHOLOGY OF FIELDS 

arteries upon the chiasm. The remarkable distortion 
and alteration of the visual tracts which are observed 
in disease in and about the chiasmal region of the 
brain, without any marked field defects, are facts 
worthy of note and will illustrate the amount of 
pressure and damage which the chiasm may undergo 
without marked perimetric evidence of disease. 

Visual Fields in Glaucoma. — Two types of glau- 
coma are recognized: (i) the acute inflammatory; 

(2) the chronic non-inflammatory variety. Clinically, 
other classifications may be made, but for purposes 
of perimetric study this simple division will suffice. 
It must be conceded, too, that the simple non-in- 
flammatory type may at any time develop an acute 
fulminating exacerbation, and that the acute inflam- 
matory variety may, and usually does, become the 
basis of the chronic non-inflammatory glaucoma. 

In glaucoma, recognized departures from the normal 
field manifest themselves: (1) in the early loss of the 
nasal field; (2) contraction of form and color fields; 

(3) marked contraction of the periphery with preserva- 
tion of central vision for form and color; (4) sector-like 
defects, especially in the superior and inferior nasal 
quadrants; (5) scotomata of nearly every known 
variety. 

In the acute inflammatory type of glaucoma, central, 
as well as indirect vision may be reduced considerably. 
Most of the loss of central vision at least is due to 
the cloudy media, steamy cornea, etc. Peripheral 
vision, however, is more largely the result of the 
condition of the circulation. The larger area supplied 
by the temporal branches of the central artery of the 
retina, and the longer detour necessary to reach the 
most peripheral parts of the temporal area, are assigned 
as the causes for the early shrinkage of the nasal field, 
a symptom which is noted both in the acute and the 



DISEASES OF THE PAPILLA 



139 



chronic variety of glaucoma. The rod and cone 
layers of the retina, as has been shown in a previous 
chapter, receive their nourishment from the chorio- 
capillaris, and the choriocapillaris is evenly distributed 
over the entire extent of the choroid. It is probable, 
therefore, that the early loss of the nasal field in acute 
glaucoma indicates the beginning of what may be 
anticipated in the chronic variety, i. e., when nasal 
shrinkage is present in acute glaucoma the condition 
will probably become a chronic one, and the tern- 





^^\. 3 


0° \/ 


1 / 

1 / 


/\ ^ - 


""-Oa \ 


■•w 








-— \ VX i 


WJ 1 i 

3\/ 




^^-— -J 






^^~~— — .A 


2l__ ^^^ \/ 



SED. 



Fig. 67. — Indistinct scotoma in a case of chronic glaucoma. Marked cutting 

of nasal field. 



porary nutritional disturbance is later on replaced by 
an atrophic process. Shrinkage of the field in acute 
inflammatory glaucoma, as a rule, is temporary. 
When, however, contraction becomes marked, the 
fields are rarely restored to their normal limits but 
mark the beginning of the more chronic process which 
is progressive. To draw a sharp dividing line, if 
that is possible, between the field changes in acute 
and chronic glaucoma, one would say the former are 
due to vascular disturbances, whereas the latter are 
the result largely of the atrophy of the optic nerve 



140 



SPECIAL PATHOLOGY OF FIELDS 



fibers in the nerve head. Both factors are found active 
in chronic glaucoma, the atrophic stage being indirectly 




Fig. 68. — A typical field of advanced chronic glaucoma taken with a 5 
mm. test object. Central vision 6/6 in each eye. Both eyes blind to color. 
(Reber.) 

due to the shutting off of the vascular supply and 
directly to the intra-ocular pressure. It is probably 
more scientific, therefore, to regard acute inflammatory 
glaucoma as a variation, in onset at least, of a simple 




Fig. 69. — Chronic glaucoma. 



chronic non-inflammatory variety, rather than a 
distinct and separate type. 



DISEASES OF THE PAPILLA 141 

Second in frequency to the early shrinkage of the 
nasal field is the concentric contraction of both form 
and color fields. This is a late phenomenon and is 
usually most marked when the fields are well contracted. 
In fact, the degree of this concentric contraction 
furnishes a good indication for surgical intervention. 
It is characteristic of simple chronic glaucoma that 
central visual acuity is preserved until peripheral 
vision has almost disappeared in many instances, 
and the extent of the contraction is the only guide 
to the progress of the disease. If operative inter- 
ference is induced too late, little hope of saving the 
residual vision can be entertained. The necessity, 
therefore, of frequent perimetric studies in simple 
chronic glaucoma must be apparent. The extreme 
contraction of fields with preservation of central 
vision is one of the remarkable and characteristic 
phenomena of this type of glaucoma. Fields of vision 
have been found limited simply to central fixation, 
with power of orientation entirely gone, and not- 
withstanding this the patient has found it possible 
to pick out a. letter at a time and read fine print with 
difficulty. Probably one of the greatest sources of 
error and surgical neglect in chronic glaucoma arises 
from this type of defect, when perimetry is not as- 
siduously practised throughout the case. One of the 
strongest object lessons in the value of perimetry when 
practised, and the dangers of neglect in a routine 
study of cases involving the interior of the globe, 
may be found in glaucoma. Its neglect in this disease 
may well be regarded as not only inexcusable, but 
criminally responsible for subsequent blindness. 

A third type of field change observed in glaucoma 
is the sector-like defect which often extends to, and at 
times, even includes central fixation. The tendency of 
the nasal field to shrink is not only an early symptom, 



142 SPECIAL PATHOLOGY OF FIELDS 

but later is manifest in the formation of the sector-like 
defects under discussion. These defects are usually 
observed on the nasal side, and a superior or inferior 
nasal quadrant defect is therefore frequently noted. 
When associated with central or paracentral scotoma, 
a comet-shaped field may result. These reentering 
angular scotomata are probably due to disease of 
nerve-fiber bundles extending from the edge of the 
disc to the periphery. Bjerrum's method of using 
minute test objects on a black cloth or blackboard 
has enabled us to clearly define these areas with 
certainty, and this form of perimetric defect is now 
known to occur more frequently than was formerly 
supposed. Ronne 1 has discussed the relation of nerve- 
fiber defects to the nerve-fiber distribution and in a 
diagrammatic sketch shows their possible relation 
and their relation to the field. From his studies and 
the studies ot others by means of Bjerrum's method, 
defects may be traced along the course of nerve bundles 
as it were, beginning in the optic disc and extending 
out toward the periphery. The small insular defects 
so frequently found also assume a crescent shape, 
suggesting that atrophy of short bundles develops 
in a similar manner. 

Finally, not only is the peripheral field involved in 
glaucoma, but the central zone is also vulnerable, 
and when carefully sought, central, paracentral, per- 
ipheral, and ring scotomata have been observed. In 
the majority of instances scotomata will be found 
radiating from the enlarged blind spot at the center. 
This is in harmony with the belief that bundles of 
retinal nerve fibers extending from the papilla to the 
periphery become diseased at the edge of the disc 
or excavation. As a rule, central fixation remains 

1 Nerve Fiber Defects in Visual Field, Especially Nasal Field, Archiv f. 
Augenh., lxxiv, 180. 



DISEASES OF THE PAPILLA 



143 



intact, but the enlarged blind spot may extend in the 
direction of the macula and a scotoma may therefore 
include the macular region. The scotoma may be 
indistinct, relative or absolute, usually negative, in 
character. The stage of the disease will, in a large 
measure, determine this. The essential feature of the 
scotoma in this central zone is the fact that it is con- 
tinuous with the normal blind spot. In this respect 
the scotoma differs from that observed in primary 
optic-nerve atrophy and serves as a point in differential 
diagnosis. This type of scotoma as found in glaucoma 




Fig. 70. — Bjerrum's form of scotoma in glaucoma. 



is referred to by many authors as Bjerrum's symptom. 
A central scotoma may gradually enlarge in the direc- 
tion of the distribution of nerve-fiber bundles and may 
therefore reach the periphery, producing a sector-like 
defect in the field, or, as it not infrequently happens, 
peripheral scotomata are found when the field is 
carefully explored with a small object i mm. to 3 mm. 
in diameter. In the field shown in Fig. 70, Bjerrum's 
symptom is well illustrated. It is a field taken by 
Ronne. 1 

1 Archiv f. Augenh., lxxiv. 



144 SPECIAL PATHOLOGY OF FIELDS 

That the field defects are the result of an optic 
atrophy is indicated in the early loss of the red and 
green and in the behavior of the color tests, especially 
in subdued light. In the early stages of the disease, 
when examination is made in good daylight, little 
narrowing of the color fields may be observed. When, 
however, the examination is made in subdued light, 
the color fields will show marked contraction. As a 
rule, after the disease has progressed, red and green 
fields will be found reduced relatively with the form 
field, and may be totally lost, even in the macular 
region, while form is still preserved around the point 
of central fixation. 

DISEASE OF THE OPTIC NERVE PROPER. 

Disease of the optic nerve proper from the eyeball 
to the intracranial portion of the nerve, just before 
it enters the chiasm, forms a clinical group which may 
be advantageously discussed collectively. It is impos- 
sible, for example, to draw a sharp dividing line between 
choked disc and optic neuritis of the retrobulbar 
portion, as choked disc is naturally accompanied by 
an ascending optic neuritis, or may be associated with 
a descending neuritis. It is also true that an optic 
neuritis and an optic atrophy may have their origin 
in the chiasm or posterior to it; but the symptom- 
complex which characterizes a neuritis or atrophy in 
the chiasm or posterior to it differs materially from 
the group of symptoms which accompany an orbital 
retrobulbar neuritis or atrophy. Furthermore, the 
anatomic environment of this portion of the optic 
nerve predisposes it to injuries and disease not met 
with in the calvarium. The frequent infection of the 
orbit from the nose and the accessory sinuses, the 
exposure of the eye and orbit to external injury, the 



DISEASE OF THE OPTIC NERVE PROPER 145 

passage of the nerve through the small optic foramen, 
and the continuation of the subarachnoid and subdural 
spaces into the sheath of the optic nerve are further 
factors which make this part of the nerve particularly 
vulnerable. Peculiarities in the relation of the chiasm 
and optic tracts to other parts of the brain and skull, 
on the other hand, render that part of the optic tract 
susceptible to diseases characterized by special symp- 
tom groups. 

Optic Neuritis. — The retrobulbar portion of the 
optic nerve is subject to two types of diseases — neuritis 
and atrophy. Three types of neuritis are recognized: 
(i) diffuse interstitial neuritis; (2) neuritis of the 
papillomacular bundle; (3) perineuritis. The first and 
third types are similar, and probably differ only in 
degree, as a perineuritis, if at ail severe, will eventually 
become a general neuritis. The second form of neuritis, 
in which the papillomacular bundle is especially in- 
volved, is a distinct type of disease in which a central 
scotoma is a rather constant feature. Two types are 
recognized, the acute and chronic, the latter also 
being known as toxic amblyopia, although by some 
toxic amblyopia is regarded primarily as a disease of the 
ganglionic cells in the retina with secondary involve- 
ment of the optic-nerve fibers. 

The diffuse interstitial type of retrobulbar neuritis 
may or may not be associated with the papillitis. 
Cases are usually accompanied by a swelling of the 
nerve head. Changes in the fields usually take the 
form of irregular peripheral contraction of both form 
and color fields, with a tendency to sector-like defects. 
This is especially apt to develop when the neuritis is 
due to phlegmon of the orbit, sinus disease, or any 
local orbital disease. Under these circumstances, 
neuritis may develop first, by extension of the inflam- 
mation, and a local inflammation of the optic nerve 
10 



146 SPECIAL PATHOLOGY OF FIELDS 

will mark the beginning of diffuse optic neuritis which 
probably will supervene. Under such circumstances, 
a papilledema may accompany the neuritis, and 
changes in the central part of the field will be associated 
with sector-like defects and contraction of the per- 
ipheral field. An enlarged blind spot may be the 
only evidence of changes in the central field ; or scoto- 
matous areas extending from the blind spot, indistinct, 
relative, or absolute in type, may be observed. The 
usual ophthalmoscopic appearance of the fundus may 
be found, although in the early stages of the disease, 
fundus details may not account for the marked peri- 
metric changes which may be present from the 
beginning. This is peculiar to retrobulbar neuritis, 
although rather more characteristic of the chronic 
variety or true retrobulbar neuritis. 

The extent of perimetric changes, both peripheral 
and central, will depend upon the extent and duration 
of the neuritis. During the regressive stage of a severe 
optic neuritis with papilledema, a marked improve- 
ment in the field may become apparent together with 
improvement of central vision. This recovery, how- 
ever, may be of short duration, as the consecutive 
atrophy which is apt to follow may bring about a 
shrinkage in the fields far in excess of the contraction 
observed in the inflammatory stage. On the other 
hand, residual perimetric changes may be slight, even 
after severe forms of optic neuritis with marked 
fundus changes. This is well shown in Fig. 71. The 
fields at this time are well preserved, two years after 
a severe retrobulbar neuritis. The fundus shows a 
disc almost obscured by exudate, retinal vessels 
buried here and there by retinal haze, vessels tortuous, 
with total absence of light streaks and a fundus which 
is hazy throughout. The degree of recovery will be 
determined by the amount of consecutive atrophy 



DISEASE OF THE OPTIC NERVE PROPER 



147 



present, and the ophthalmoscopic findings may be out 
of proportion to the perimetric studies. 

Field Changes in Posterior Accessory Sinus Disease. — 
Our attention of late has been drawn to the presence 
of an enlarged blind spot as an early evidence of disease 
of the posterior nasal sinuses. Others have found a 
central scotoma present in a large percentage of cases, 
and ring scotomata have been recorded. A careful 
study of the cadaver shows the close relation which 
necessarily exists between inflammation of the sphe- 
noidal sinus and optic nerve disease. As the nerve 




Fig. 71. — Retrobulbar neuritis, postinflammatory stage. 

passes through the optic foramen a thin wall of bony 
tissue separates it from the sphenoidal sinus. When 
this sinus is distended or the seat of disease, the optic- 
nerve sheath may share in the inflammation very 
early. Because of the extreme vulnerability of the 
more highly organized papillomacular bundle of nerve 
fibers, this part of the nerve may be first to show 
evidence of the disease if carefully investigated. 
Van der Hoeve's contention 1 that an enlargement of 
the blind spot for colors is observed before a central 
scotoma, has been confirmed by others. During the 

1 Archiv f. Augenh., lxvii, 101. 



148 SPECIAL PATHOLOGY OF FIELDS 

progress of the disease a central scotoma and the 
enlarged blind spot may become united. 

Enlargement of the blind spot has been reported 
in disease of the sphenoid, posterior ethmoid, anterior 
ethmoid, antrum and in frontal sinusitis. If present 
in frontal sinusitis, and even in antral disease, it is 
evidence of bone necrosis or at least of advanced 
disease. In exceptional instances, however, the infec- 
tion may be carried by the blood stream. Because 
of the proximity of the posterior ethmoid and sphenoidal 
cells, optic nerve symptoms may be present before 
necrosis of the bone has taken place, either by means 
of the blood streams as carriers of infection or by a 
simple congestion. The dura mater covering the nerve 
is continuous with the periosteal covering of the bone 
in the optic foramen. An inflammation, therefore, 
may promptly spread from the air spaces to the nerve 
and produce a perineuritis. If the peripapillary nerve 
fibers of the retina are located in the periphery of the 
optic nerve, as claimed by Fuchs, early enlargement 
of the blind spot in posterior sinus disease is easily 
explained. 

Characteristically, the first evidence of enlargement 
is an indistinct zone surrounding the disk in which 
color values are doubtful. Then follows a relative 
enlargement for colors, and finally an absolute enlarge- 
ment. In most cases one can clearly demonstrate 
an absolute enlargement surrounded by a relative zone 
of color loss, and beyond this an indistinct zone for 
colors. 

It is not clear just how an uncomplicated frontal 
sinusitis can produce an enlargement of the blind spot. 
Such cases have been reported in literature, and in 
Fig. 74 is recorded the field of a case of frontal sinu- 
sitis studied by Posey. This case was associated with 
orbital infiltration on one side and. the report of the 



DISEASE OF THE OPTIC NERVE PROPER 



149 



rhinologist, Dr. George B. Wood, suggested some 
involvement of the ethmoid cells. 

A few investigators have found some changes in the 
form field. A more careful search of the peripheral 
fields in these cases, before ophthalmoscopic changes 
are visible, may reveal more extensive damage to the 
peripheral form and color fields than are now recorded. 
The insensitive and functionally less active periphery 




Fig. 72. — Ethmoid and antrum 
disease of long standing. Contrac- 
tion of form and color fields. En- 
largement of Mariotte's blind spot. 



Fig. 73. — Ethmoid and antrum 
disease. Necrosis of orbital wall. 
Blind spot enlarged for form, sur- 
rounded by a relative enlargement 
for colorand an indistinct scotomatous 
area beyond. Form and color fields 
contracted. 



is not searched with the same care which is usually 
employed in the central zone. Ring scotomata have 
been also, recorded in a few cases, but this phenomenon 
is too infrequently observed, and the possible relation 
of hysteria as a causitive factor should receive due 
consideration before attributing this form of scotoma 
to posterior sinus disease. 

In some of the more obscure forms of posterior sinus 
disease, a careful perimetric study may be of definite 



150 



SPECIAL PATHOLOGY OF FIELDS 



diagnostic value; and in the more apparent forms a 
study of the fields becomes necessary in order to 




Fig. 74. — Enlargement of Mariotte's blind spot in frontal sinusitis. (Posey.) 

guide the operator in making his decision as to when 
to operate. If ophthalmoscopic changes are not too 
much in evidence, the prognosis for recovery of the 
form field after operation is good. One cannot hope, 
however, to restore fields which have been reduced 
by a well-defined atrophy. 




Fig. 75. — Enlarged blind spot. Chronic posterior ethmoiditis. 



True Retrobulbar Neuritis. — True retrobulbar neuritis 
occurs as an acute and chronic variety. In the former, 



DISEASE OF THE OPTIC NERVE PROPER 



151 



the loss of the central field of vision from involvement 
of the papillomacular bundle is not so much in evidence, 
or at least occurs only as a part of a rapid and diffuse 
inflammation of the optic nerve. During the course of 
twenty-four to forty-eight hours central vision may 
be reduced to the counting of fingers at a foot, and 
peripheral vision will be reduced proportionately. 
The perimetric symptoms will depend upon the degree 
of the inflammation and the extent of the subsequent 
atrophy. Central scotoma, however, is not so fre- 
quently in evidence as in the chronic variety. 




Fig. 76. — Acute retrobular neuritis, four days after onset. 



In Fig. 76 are recorded the fields of a boy of seventeen 
years who suffered from a most violent retrobulbar 
optic neuritis, tubercular in origin, four days before 
the above fields were taken. Green was entirely lost, 
and red and form fields were reduced considerably. 
Recovery in this case was rapid but not complete. 
Central vision became 20/70 in each eye. Form fields 
enlarged to fairly normal limits, but red remained 
contracted, and green became visible in the central 
field. 

Toxic Amblyopia. — Toxic amblyopia, or the chronic 
variety of true retrobulbar neuritis, perimetrically is 



152 



SPECIAL PATHOLOGY OF FIELDS 



as distinctive and characteristic as the clinical phe- 
nomenon which characterizes it. (Toxic amblyopia may 
begin in the ganglionic retinal cells, and secondarily 
may spread to the nerve fibers or the papillomacular 
bundle. Ordinarily, however, it is classified as a 
type of retrobulbar neuritis.) Bilateral pericentral 
scotomata is the rather uniform perimetric finding in 
this condition. Lohmann calls attention to Edinger's 
dictum "that a high degree of functional activity 
involves an increased morbidity," as especially 
applicable to the papillomacular bundle of the optic 




Fig. 77. — Toxic amblyopia. 



nerve. The process usually seems to be limited to this 
part of the optic nerve, although the peripheral field 
has been found to be involved in some instances. 
Subjectively, the patient complains of a haziness in 
central vision, indirect vision remaining normal. This 
blind area is bilateral and is negative in character; 
that is, although the patient may be conscious of 
a haze, the disturbed area can only be mapped out by 
perimetry. 

The blind area forms a horizontal oval area which 
includes the macula, and may include the blind spot 
of Mariotte. It may either be relative or absolute. 



DISEASE OF THE OPTIC NERVE PROPER 



153 



The stage and severity of the neuritis will determine 
this. A characteristic of this form of central scotoma 
is the presence of an absolute scotoma in a large 
relative area. The scotoma for white and blue will 
be smaller than that for red and green, the absolute 
blind spot being situated centrally or eccentrically 
in the relative area. Bar 1 believes that two absolute 
scotomata may be found present — one in the macula 
and one in the normal blind spot, being connected 
by a band of relative scotoma. The oval area extends 




Fig. 78. — Toxic amblyopia. Typical absolute scotoma in a relative area. 
Form fields normal. (Reber.) 

from the macula toward the optic disk. The scotoma 
is therefore usually pericentral rather than central. 
If the peripheral field is involved, Bar believes it is an 
indication of the involvement of the central nervous 
system. 

In Fig. 79 are recorded the fields of retrobulbar 
neuritis of obscure origin. The central blindness 
followed the removal of a foreign body from the cornea. 
Although central vision is now reduced to 20/40, the 



1 Archiv f. Augenh., liv, 291. 



154 



SPECIAL PATHOLOGY OF FIELDS 



scotoma is just beneath the point of fixation and is 
connected with the enlarged blind spot by an area 
blind to colors but not to form. 



o- L 




Fig. 79. — Retrobular neuritis of obscure origin. Enlarged blind spot of 
Mariotte. Relative and absolute scotomata. 

Perimetry is of value in making a prognosis in this 
form of optic-nerve disease. As green is the first color 
to disappear, it is also the last to be recovered, if 





Fig. 80. — Toxic amblyopia of diabetic origin, (Reber.) 

recovery is complete. If recovery takes place, the 
absolute scotoma may become smaller, and blue may 
be restored, followed in order by red and green. In 



DISEASE OF THE OPTIC NERVE PROPER 155 

severe cases, recovery is rarely complete. A relative, 
and sometimes an absolute, scotoma will remain. 

It is interesting to recall the article of Fergus which 
appeared in the British Medical Journal, December 
29, 1906, on "Sympathetic Amblyopia." Fergus 
found a condition in sympathetic ophthalmia which 
he called sympathetic amblyopia. In the cases referred 
to, inflammatory symptoms were absent, and peri- 
metrically Fergus found a concentric contraction 
with some, but not complete, amblyopia. These 
observations have been confirmed by other investi- 
gators, and in some instances an oval central scotoma, 
characteristic of toxic amblyopia, was found. 

Field Changes in Optic-nerve Atrophy. — 
Clinically, optic-nerve atrophy may be divided into: 
(1) primary; (2) consecutive or postneuritic; (3) 
secondary atrophy; (4) retinic or choroiditic atrophy. 
Discussion of optic-nerve atrophy cannot be limited 
to the intra-orbital portion of the visual tract, as many 
of the primary and consecutive atrophies do not 
originate within this part of the optic nerve. For 
convenience of discussion, however, atrophy due to 
disease of any part of the optic tract will be dealt 
with at this time. Essentially, each of these four 
clinical varieties has certain perimetric symptoms 
which are common to all. Color fields, especially the 
red and green, show evidence of shrinkage out of pro- 
portion to the form, yellow and blue fields. The form 
field suffers in any variety of atrophy, and the con- 
traction may be either of the concentric type or may 
be marked by reentering angles. Scotomata, central 
or peripheral, indistinct, relative or absolute, usually 
negative in character, also appear in all varieties. 
There are, however, shades of difference more or less 
constant which distinguish one variety from another. 
For example, primary atrophy of systemic origin 



156 SPECIAL PATHOLOGY OF FIELDS 

usually is characterized by a concentric contraction 
of form and color fields, whereas consecutive or post- 
neuritic atrophy is marked by an irregular contraction 
with large reentering angles. Although this is the 
prevailing order, exceptions are numerous. Primary 
atrophy due to insular sclerosis usually is the exception, 
and irregularities in this disease are the rule. Another 
example of prevailing differences is observed in retinitic 
and choroidal atrophy in which scotomata and other 
perimetric changes peculiar to the primary retinitis 
and choroiditis prevail in contrast to the more regular 
types of primary atrophy in which scotomata are not 
so much in evidence. 

Primary Atrophy. — This classic type is probably 
the most important of the subdivisions under discus- 
sion. It includes a large number of hereditary and 
acquired systemic diseases, local pathologic processes, 
as well as a fairly large unclassified group such as 
atrophy due to exposure to cold, venereal excesses, 
malnutrition, etc. Tabes dorsalis, or locomotor ataxia, 
is the classic example of this variety. An early and 
rapid loss of red and green fields, together with con- 
centric contraction of form, yellow and blue fields, 
are the usual phenomena. The nasal field, as a rule, 
shows the first evidence of change. Central scotomata 
are not unusual. These scotomata, when present, 
are negative in type, and although relative at first, 
soon become absolute. The concentric contraction 
in typical cases progresses until all evidence of color 
has disappeared and only central fixation remains, 
or complete blindness supervenes. Instead of this 
regular and concentric contraction, irregular types 
are observed. The nasal field may show cutting, 
corresponding to the early pallor of the temporal half 
of the optic discs. Quadrant and reentering angles, 
especially of the nasal field, early loss of fixation from a 



DISEASE OF THE OPTIC NERVE PROPER 



157 



central scotoma, total loss of all light and color sense, 
excepting in a small area eccentric to the temporal 
side of the field, are occasionally observed. Price and 
Heed 1 report a case of binasal hemianopsia occurring 
in a supposed tabetic patient. Two other cases of a 
similar character were collected by Shoemaker 2 in 1905. 
Insular Sclerosis and Paresis. — Insular sclerosis and 
paresis show perimetric changes of varying character. 
The irregularity in the findings is most characteristic, 
and is in harmony with the varying character of the 
clinical phenomena. Pallor of the temporal halves 




Fig. 81. — Binasal hemianopsia of tabetic origin. (Case reported by Price 

and Heed.) 



of the disc, more marked in one eye than in the other, 
is accompanied by irregular contraction of the form 
fields. Central, indistinct, relative or absolute, negative 
scotomata are quite as constant as any of the peri- 
metric changes observed. No constant perimetric 
changes, however, are observed, as the lesions in both 
of these conditions are irregularly distributed. Quad- 
rant and hemianopic blindness, however, occur from 
lesions in the chiasm or in the tract posterior to it. 

1 Journal of the American Medical Association, March 7, 1914, lxii, 271. 

2 New York Medical Journal, February, 1905. 



158 



SPECIAL PATHOLOGY OF FIELDS 



In Fig. 82 are recorded the fields of a classic case of 
insular sclerosis with absolute bitemporal scotomata 
and bitemporal hemianopsia for colors. These peri- 
metric symptoms remained constantly during the last 
two years of the patient's life. The form fields, how- 
ever, contracted gradually. Death came before blind- 
ness supervened. 

Paralysis Agitans. — Optic atrophy does not occur 
in uncomplicated cases of paralysis agitans. This 
disease, however, frequently develops in subjects 
suffering from a general arteriosclerosis, and perimetric 




Fig. 82. — Insular sclerosis. Bitemporal hemiachromatopsia. Bitemporal 
absolute scotomata. 



changes may therefore be observed in such subjects. 
Atrophy is not unusual in this complication, owing 
to the frequent attacks of angiospasm, which may 
result in permanently blind areas. Irregular scotomata, 
quadrant and even hemianopic in type, may be elicited 
by perimetric study. When, therefore, perimetric 
changes are observed in paralysis agitans, it may be 
assumed that they are the result of the complications. 
It is alleged that optic atrophy occasionally occurs 
in chronic myelitis, spastic paraplegia, syringomyelia, 
and in bulbar paralysis. Gowers observed optic 



DISEASE OF THE OPTIC NERVE PROPER 159 

atrophy in an uncomplicated case of chronic myelitis. 
It is doubtful whether similar conditions have been 
frequently observed in pure types of this affection 
of the spinal cord. If present, it strongly indicates 
complications. 

Cases of atrophy in Friedreich's ataxia have also 
been occasionally observed. It more frequently 
happens in hereditary cerebellar ataxia, a symptom 
group which is now separated from that of Friedreich's 
ataxia. In either case, the presence of atrophy raises 
the question of a possibly luetic condition, although 
a few undoubted cases have been reported in literature 
in pure types of Friedreich's ataxia and hereditary 
cerebellar ataxia. 

In hereditary optic-nerve atrophy, the atrophy 
accompanying skull deformities (tower-shaped skull, 
an hereditary affection) there is nothing in the peri- 
metric findings which differs materially from a simple 
primary optic atrophy. A progressive and concentric 
contraction of form and color fields is observed and 
central scotomata are frequently in evidence. 

Leber's Disease. — In Leber's disease, however, a 
form of hereditary optic atrophy, distinct types of 
field changes have been noted. An absolute or relative 
central scotoma with fairly normal fields for form is 
most characteristic. Posey reports the histories of 
two family groups of Leber's disease in which these 
characteristics are present. In the first group of three 
cases all the patients are males, the first case being 
a maternal nephew of the second, and the second a 
nephew of the third on the mother's side. This is 
the usual order of heredity. The disease is bequeathed 
to the male offspring through a healthy mother. 
The first and second cases have fairly normal form 
fields, and in each of the three cases an absolute central 
scotoma is present. 



160 



SPECIAL PATHOLOGY OF FIELDS 




Fig. 83 




Fig. 84 




FORM 

RED 

HO MMJtSI OBJECT 

Fig. 85 




Figs. 83, 84, and 85.— A family group of Leber's disease. (Dr. Wm. Campbell 

Posey.) 



DISEASE OF THE OPTIC NERVE PROPER 



161 



In Posey's second family group the heredity is not 
so characteristic, the patients being father and son, 
but the fields are especially characteristic. Form 
fields are normal in both cases, but color fields are 
reduced and there is a central scotoma in each case, 
absolute in the son and relative in the father. 




Fig. 86. — Second group of Leber's disease. (Posey.) 



Embolism and Thrombosis of the Central Artery of the 
Retina. — Embolism and thrombosis of the central artery 
of the retina, or one of its branches, is a not unusual 
cause of primary atrophy. Fig. 64 illustrates the peri- 
metric changes in this condition. In addition to the 

total loss of form and color fields in the area supplied 
11 



162 SPECIAL PATHOLOGY OF FIELDS 

by the occluded vessels, form and color fields in the 
apparently normal half are contracted. The ophthalmo- 
scopic examination shows an optic disc apparently 
normal in its upper half, but pale and atrophic with 
contracted vessels in the lower half. This patient 
suffered from embolism of the inferior branch of the 
central artery of the retina. 

Seconday Atrophy. — Secondary atrophy of the optic 
nerve is the form of atrophy which is observed after 
an injury to the optic nerve or other acute process 
which rapidly destroys the anatomic structure of the 
nerve. As a rule, ophthalmoscopic changes are only 
to be seen some time after the injury: for example, 
a blow on the skull is apt to cause this type of atrophy 
which may manifest itself only after the lapse of one 
or two months. It is a type of atrophy more apt to 
be unilateral than bilateral, but resembles primary 
optic atrophy in ophthalmoscopic findings and peri- 
metrically. It differs from the primary variety in the 
greater contraction of the arteries and veins, in the 
chalky whiteness of the disc, and the less clearly 
defined edge of the disc. In either variety, in marked 
contrast to the postneuritic type of atrophy, the 
character of the inflammation is mild. In the early 
stages of either form, however, there may be evidence 
of congestion and of low-grade inflammation. 

Perimetric studies are similar to those observed in 
primary optic atrophy. Concentric contraction of 
both form and color fields, with little disturbance 
of the central field other than gradual loss of central 
vision, are the usual perimetric findings. Central and 
paracentral scotomata may be present. They are the 
exception rather than the rule. 

Postneuritic, or Consecutive, Atrophy. — Postneuritic, 
or consecutive, atrophy is the type of atrophy observed 
after an optic neuritis or choked disc. Preceding this 



DISEASE OF THE OPTIC NERVE PROPER 163 

form of atrophy, the usual symptoms of optic neuritis 
are present. The extent of the atrophy will be deter- 
mined by the severity and duration of the optic neuritis. 
The dark room findings are in marked contrast to 
the primary varieties. The disc, as a rule, is of a 
dirty-gray color, and the details of the disc are obscured 
by the inflammatory exudate which fills in the shallow 
cup. The outline of the disc is poorly defined. 

Perimetric findings are less marked than one would 
expect, either in the inflammatory or in the regressive 
stage when atrophy is well established. In fact, it is 
a type of atrophy in which the prognosis is good, as 
compared to the primary and secondary types. 
Irregular contraction of form and color fields is most 
frequently observed. Large reentering angles extending 
to the point of fixation are usual. If the inflammation 
occurs along the optic nerves, the chiasm or tracts, 
as in gumma of the base of the brain, the papillomacular 
bundle may be involved, and central and peripheral 
scotomata, unilateral and bilateral, may be found. 

It is interesting to note, however, that a neuritis 
or papilledema of marked severity may subside with 
comparatively little atrophy, and consequently with 
few perimetric changes in form and color fields. This 
is especially true of syphilitic optic neuritis if suitable 
treatment is instituted, and in tumor of the brain if 
decompression is practised reasonably early so as to 
relieve the intra-ocular pressure. 

It is quite evident that disease along the course of 
the visual. tract, from the eyeball to the primary optic 
centers, may produce an atrophy, either of the post- 
neuritic or of the secondary type. Slowly developing 
processes which gradually destroy the integrity of the 
nerve structure are usually followed by the secondary 
type of atrophy. On the other hand, processes which 
excite a violent inflammation of the optic nerve, as a 



164 



SPECIAL PATHOLOGY OF FIELDS 



tumor of the brain pressing on or involving the visual 
tract, and at the same time large enough or so situated 
as to cause choked disc, may be followed by the post- 




Fig. 87. — Bitemporal hemianopsia caused by gumma of the center of the 

chiasm. 

neuritic variety. In the majority of instances a mixed 
type of atrophy is observed. Fig. 87 shows the field of 
a patient who suffered from a gummatous meningitis 




Fig. 88. — Altitudinal hemianopsia. Gumma of the under surface of the 
chiasm. Absolute central scotomata which later disappeared. 



of the center of the chiasm. The discs in this case are 
white, edges well-defined, arteries contracted, and 
cribriform membrane invisible because of the filling 



DISEASE OF THE CHIASM 165 

in of inflammatory exudate. Fig. 88 is the field of a 
similar case of gumma of the under surface of the 
chiasm, which gave rise to an altitudinal hemianopsia 
and an absolute central scotoma in each eye. The 
scotomata finally disappeared, leaving a permanent 
superior altitudinal hemianopsia. 

Optic atrophy caused by disease of the chiasm and 
optic tracts posterior to the chiasm will be discussed 
more fully under Chiasmal and Optic-tract Disease. 

Optic Atrophy following Disease of the Choroid 
and Retina. — A fourth type of optic atrophy is that 
observed as a result of disease of the choroid and retina. 
Clinically, this type of atrophy resembles especially 
primary atrophy. The best example of this variety 
is seen in retinitis pigmentosa, and the most character- 
istic phase of the atrophy is a marked contraction of 
both arteries and veins. 

The perimetric findings are those observed in primary 
optic atrophy with the addition of the field changes, 
which are characteristic of the primary disease. As 
disease of both retina and choroid is marked by central 
field disturbance, scotomata — central, peripheral and 
annular — this form of field change is constantly to be 
observed in the type of atrophy which follows disease 
of the choroid and retina. A most varied and irregular 
perimetric field is characteristic. 

DISEASE OF THE CHIASM. 

Perimetric studies in disease of any part of the 
visual tract have localizing value. In no part of the 
tract, however, are the findings so definitely localizing 
as in disease in and about the chiasm. A knowledge, 
therefore, of some of the more important structures 
immediately surrounding the chiasm and likely to 
become the seat of disease, is quite as important as a 



166 



SPECIAL PATHOLOGY OF FIELDS 



LEFT 




S-fUi-10 — 180 "~ - (30 

FlG. 89. — 5-24-10, when first observed. Bitemporal hemianopsia. 
o o 



LEFT 



RIGHT 




ZO-5-XO 

Fig. 90. — 10-5-10, after treatment. Bitemporal hemiachromatopsia persisting. 



RIGHT 




4'13'tt "" «80 "~ *"" 180 

Fig. 91. — 4-13-11, after treatment. Bitemporal hemiachromatopsia persisting. 



DISEASE OF THE CHIASM 



167 



LEFT 



«5-n*nni™iminmJ5 RIGHT 




3'1+lH 



Fig. 92.— 3-14-12, recovery. 




6-6-13 

Fig. 93. — 6-6-13, relapse with altitudinal hemianopsia in right eye. 

'* « RIGHT 




Z-Z2-14 — i8o 

Fig. 94. — 2-12-14, complete recovery under glandular therapy. 

Figs. 89 to 94. — Dr. B. F. Devitt's case of pituitary disease, cured by thyroid 
and pituitary extracts. 



168 SPECIAL PATHOLOGY OF FIELDS 

knowledge of the anatomy of the chiasm in interpreting 
the perimetric findings incident to disease. Surrounded 
by the meninges, the chiasm rests upon the sphenoidal 
bone. Posterior to it is the infundibulum. In the 
sella turcica is the pituitary body, and directly above 
is the anterior end of the third ventricle. To either 
side of the chiasm are the internal carotid arteries. 
Pathologic changes in structure and function of the 
chiasm are usually the result of disease of one or more 
of the structures mentioned above. 

In Figs. 89 to 94 are recorded the fields of a case of 
pituitary disease which was under the care of Drs. 
B. F. Devitt, Joseph Clothier, and Wendell Reber. 
So remarkable has been the course of this case that 
it is worthy of record. 

At the onset, the special eye phenomenon was 
bitemporal hemianopsia. Five months later, form 
fields had partly recovered under the use of thyroid 
and pituitary extracts. Color fields, however, remained 
hemianopic. Under continued treatment, recovery was 
complete in about twenty months. A year later, how- 
ever, the patient relapsed and altitudinal hemianopsia 
appeared in the right eye, with marked irregular 
contraction of the form and color fields in the left. 
Under the same glandular therapy, recovery was 
complete in eight months, and the patient has since 
then remained normal. 

The unusual features are: (1) the bitemporal hemi- 
anopsia which gradually recovered under glandular 
therapy; (2) a relapse with the development of alti- 
tudinal hemianopsia, which again completely recovered 
under similar therapy. 

In Figs. 95 to 100 are some of the variations observed 
in chiasmal disease of pituitary origin. They are 
selected from Cushing's interesting volume on Pituitary 
Disease, and are representations of the clinical types 



DISEASE OF THE CHIASM 169 

ordinarily observed. No part of the visual path, 
however, is subject to greater variation from the 
average type of change than the chiasm, and fields 
bizarre and heterogeneous are a usual phenomenon 
when the chiasm is the seat of disease. 

Luetic, tubercular, and traumatic meningitis are 
probably the most frequently observed, although 
disease of the pituitary body is also a common cause 
of chiasmal changes. Remote or proximal intracerebral 
esions are often accompanied by distention of the 
third ventricle, which in turn may press upon the chiasm 
and produce types of hemianopsia. Cases of this kind 
have been reported. Less frequently, a bony exostosis 
has encroached upon the chiasm and sclerosis of the 
internal carotid arteries have been reported as etiologic 
factors in chiasmal symptoms. 

The diagnostic perimetric symptoms of disease of 
the chiasm are bitemporal and binasal hemianopsia, 
irregular hemianopsias which may have begun or may 
terminate as one of these types, and the altitudinal 
hemianopsias. The chiasm is composed of crossed 
and uncrossed fibers. The relation of the position 
of the nerve fibers in the chiasm, as well as in the optic 
nerves and tracts, to the various quadrants of the 
retina, has been established. The nerve fibers of the 
under surface of the chiasm are associated with the 
ganglionic layer of the inferior retinae, and the upper 
part of the chiasm with the superior retinae. In a 
similar manner, the outer or uncrossed fibers proceed 
from the temporal halves of the retinae and the middle 
or crossed fibers proceed from the inner halves of the 
retinae. If the chiasm is completely severed antero- 
posteriorly the crossed nerve conductivity is entirely 
destroyed, the inner halves of both retinae become 
blind, and the type of hemianopsia known as bitemporal 
hemianopsia will be the perimetric finding. The 



170 



SPECIAL PATHOLOGY OF FIELDS 



LEFT 15 



RIGHT 




FlG.[96 




DISEASE OF THE CHIASM 



171 



LEFT J 




Fig. 98 



RfGHT 




Fig. 100 
Figs. 95 to 100. — Field changes observed by Cushing in pituitary disease. 



172 SPECIAL PATHOLOGY OF FIELDS 

temporal fields in each eye will be totally blind. In 
this complete form of half- vision, the dividing line 
between the seeing and the blind part of the retina 
may be one of several types. A fairly straight line may 
be found passing through and including the macula, 
as in Fig. 36. More frequently, however, the macula 
escapes, as in Fig. 38. This is due to the fact that each 
macula is probably represented on both sides of the 
brain. In other cases, not only the macula escapes, 
but also an area above and below the macula toward 
the periphery of the field will be found intact, as shown 
in Fig. 39. This condition is spoken of as an overshot 
field. A fourth variation is that shown in Fig. 37, in 
which the dividing lines are oblique rather than 
straight. The two latter conditions can be attributed 
to differences in anatomic distribution of the crossed 
and uncrossed nerve fibers in different individuals. 

The dividing line for color is practically the same as 
that for form in a complete hemianopsia. In a slowly 
developing case, however, color may, and in all prob- 
ability will, progress more rapidly than that for form, 
as color changes are the earliest evidence of optic- 
nerve atrophy. (See Fig. 82.) 

Less frequently observed is the pure type of binasal 
hemianopsia of chiasmal origin. Two lesions are 
necessary to produce this type of field. The chiasm 
must be injured or pressed upon on both sides to 
produce the condition. Isolated instances of advanced 
sclerosis of the internal carotid arteries have been 
found at autopsy in cases which during life presented 
this form of hemianopsia. Inflammatory processes 
about the chiasm in which the center of the chiasm 
escapes might be responsible. Cushing has observed 
this form of hemianopsia in a number of cases of 
pituitary disease. The condition is exceedingly rare 
as a clinical phenomenon. 



DISEASE OF THE CHIASM 



173 



Bilateral altitudinal hemianopsia is usually of 
chiasmal origin and occurs more frequently than text- 
books and literature would seem to indicate. Figs. 
88 and 101 are the fields of a case of superior altitudinal 
hemianopsia which the author had under his observa- 
tion for a number of years. In Fig. 88 the disease 
was at its height, and Fig. ioi was the final result. 
It was due to a gumma of the inferior part of the 
chiasm. Inflammation of the upper surface of the 
chiasm will cause inferior altitudinal hemianopsia. 
These forms of altitudinal hemianopsia are peculiar 




Fig. 101. — Altitudinal hemianopsia. Gumma of the chiasm. 



to the chiasm or parts of the visual tract close to the 
chiasm. They occur in no other parts of the visual 
tract, unless there are very unusual symmetric bilateral 
lesions. A tumor of the central part of the cerebellum, 
pressing upward equally on both cuneiform bodies, 
might cause an irregular form of bilateral superior 
altitudinal hemianopsia. Such a condition, however, 
must necessarily be exceedingly rare. 

Types of chiasmal complete hemianopsia under 
discussion are less frequently observed than incomplete 
and irregular forms. For example, a lesion located 
in the center of the chiasm will give rise to bitemporal 



174 



SPECIAL PATHOLOGY OF FIELDS 



hemianopsia. If, however, the process begins or 
develops a little to the side and back of the chiasm, 




Fig. 102. — Right and left fields of a case of gumma of the upper part of the 
chiasm. Bitemporal inferior quadrant anopsia, absolute in the left eye, 
relative in the right. Bitemporal hemianopsia for green 

involving the optic tract, homonymous hemianopsia 
of the right or left half of each retina will be found. 




Fig. 103. — Fields taken one week after Fig. 102. Patient under anti- 
syphilitic treatment. Hemianopsia for green gradually disappearing. Absolute 
enlargement of both blind spots, greater enlargement for blue, and largest for 
red. 

Figs. 102 and 103. — Gumma of the chiasm. 

If the process develops in the direction of the chiasm, 
the crossed fibers going to the opposite side of the 



DISEASE OF THE CHIASM 



175 



brain may be destroyed, and the patient will therefore 
have a totally blind field in the eye on the side of the 
lesion and a blind temporal field in the opposite eye. 
In a similar manner, a lesion in the center of the chiasm 
may extend to the right or left and produce, in addition 
to the bitemporal hemianopsia, total blindness in the 
eye to the side toward which the disease extends. 
A lesion beginning at the outer side of the chiasm, 
giving rise to half-blindness (nasal) in the eye on the 
same side as the lesion, may rapidly develop into total 




Fig. 104. — Left homonymous hemianopsia. Hemorrhage into right optic 
thalamus. Fundus changes slight. Fields taken five months after onset. Pain 
in paralyzed arm and leg severe. 



blindness in the eye, if anterior to the chiasm, homony- 
mous hemianopsia, if posterior to the chiasm, and total 
blindness in the eye on the side of the lesion and 
temporal blindness of the opposite eye, if the crossed 
fibers are involved. Inasmuch, therefore, as the 
chiasm is small and inflammatory processes irregular, 
these mixed types of hemianopsia are more frequently 
observed than the pure chiasmal hemianopsia. (See 
Figs. 95 to ioo.) 

When the cause of commissural change is disease 
of the pituitary body, nerve changes are slow in making 



176 SPECIAL PATHOLOGY OF FIELDS 

their appearance because the nerve fibers readily 
adjust themselves to the slowly developing tumor 
formation. The earliest symptom may be a shrinking 
in the upper outer quadrant of one or both fields. 
Color changes, as a rule, precede form, and a fairly 
well-defined color hemianopsia may be established 
before a change in the form field is noted, or only a 
moderate contraction of the upper, outer quadrant 
is in evidence. Bitemporal color hemianopsia, or be- 
ginning contraction of the upper, outer quadrants for 
form and color, are therefore suggestive of beginning 
commissural invasion, and careful studies of the com- 
missural region should be made by the roentgenologist 
in such cases. 

Central amblyopia is frequently noted as a symptom 
of pituitary and other perichiasmal disease. It may 
be of a fleeting character, unilateral or bilateral, or 
it may mark the beginning of a central scotoma. 
It is a well-known fact that the papillomacular bundle 
is more susceptible to toxic and organic influence 
than other parts of the nerve, and disease about the 
chiasm is no exception to the rule, notwithstanding 
the supposed double innervation of the maculae. 
Central scotomata may be an early or late phenomenon, 
or as in many instances, totally absent. 

Atrophy of the optic nerve is visible, as a rule, 
although tardy in disease of the chiasm. Field changes 
are therefore not limited to the hemianopic blind areas, 
but contraction for form and colors in other parts 
of the field will be frequently observed. Disease due 
to the extension of the pathologic process to all parts 
of the chiasm, and bizarre types of fields, will occasion- 
ally render a diagnosis difficult in the absence of other 
clinical evidence. 

It is also possible to find a hemianopic field compli- 
cated by hysteria. In such instances, in addition to 



FIELDS IN DISEASE OF THE OPTIC TRACTS 177 

the hemianopsia, is added the evidence of hysteria 
in the non-hemianopic part of the field. This compli- 
cation is not a remote possibility, but an actual occur- 
rence. It is a matter of common observation that 
patients afflicted with chronic intracranial disease very 
often are the victims of hysteria; and the influence 
of frequent neurologic and ophthalmologic examina- 
tions does not tend to diminish the hysteria. With 
no tendency, therefore, to wilfully distort perimetric 
fields, but controlled by an influence which can only 
be expressed by inhibition, the most bizarre and hetero- 
geneous types of fields may be developed from time 
to time. Unless the hysterical complication is 
recognized, such fields will not only be misleading, 
but will be of absolutely no value. 

Similarly, a tumor or new growth pressing upon the 
chiasm directly or indirectly and large enough or so 
located as to produce choked disc, may cause hemi- 
anopic fields plus changes in the balance of the field 
incident to the choked disc. 

FIELDS IN DISEASE OF THE OPTIC TRACTS AND 
PRIMARY OPTIC CENTERS. 

Optic atrophy which eventually becomes visible 

by means of the ophthalmoscope is a characteristic 

feature of disease of any part of the visual tract between 

the eyeball and the basal nuclei. Disease of the 

nuclei is also accompanied by atrophy. The closer 

the focus of disease to the eyeball, the more rapid 

is the appearance of the atrophy in the nerve head. 

Disease of the tract, however, is distinguished from 

disease of other parts of the visual path anterior to 

the tract by partial atrophy and by the type of the 

hemianopsia. Atrophy, as a rule, is incomplete and 

is confined to the half of each nerve head on the side 

of the lesion. 
12 



178 SPECIAL PATHOLOGY OF FIELDS 

Perimetrically, the atrophy manifests itself by 
homonymous hemianopsia on the side opposite to the 
lesion. As in other parts of the visual path, color 
hemianopsia may precede or progress more rapidly 
than that for form, but the hemianopsia usually is 
complete, excepting in those cases in which the 
pathologic process is either very slow in developing 
or becomes arrested spontaneously, or under proper 
therapeutic influence. Unlike commissural hemian- 
opsia, unless the case is complicated by increased 
intracranial pressure, causing choked disc, or by 
hysteria, the field changes are sharp and limited to a 
right or left half-vision. In the seeing parts of the 
retina, fields of normal dimensions, both for form and 
color, will be found. The maculae are usually intact, 
as in chiasmal hemianopsia, and the variations of the 
dividing line mentioned in chiasmal hemianopsia are 
especially well exemplified. Complete hemianopsia 
is the rule, because of the compactness of the bundle 
of nerve fibers which make up the optic tract. An 
atrophy, therefore, which is visible by the use of the 
ophthalmoscope, accompanied by a homonymous form 
of hemianopsia, is pathognomonic of disease of the 
tract. 

Until very recently the Wernicke pupillary 
phenomenon and the Wilbrand prism phenomenon 
were employed as a means of differentiating between 
hemianopsia due to a lesion in or anterior to the basal 
nuclei, and above these nuclei in the optic radiations 
and cortex. Hess and others, however, paved the way 
for doubting the value of these phenomena in making 
this differentiation. More recently, Walker has made 
a careful study of these phenomena, and his con- 
clusions are that they are of no value in this localization. 
They should not, therefore, as far as our present 
knowledge goes, be depended upon as an aid in locating 



FIELDS IN DISEASE OF THE OPTIC TRACTS 179 

the lesion above or below the nuclei. (It is possible, 
however, that future study will show the Wernicke 
pupillary phenomenon may be of value in locating the 
seat of lesion in hemianopic central amblyopia, provid- 
ing the technic of the experiment can be reduced to 
scientific precision.) A careful study of hemianopsia, 
its progress, and especially its completeness, and the 
associated symptoms, must be our guide in determin- 
ing the exact location of the lesion in homonymous 
hemianopsia. Optic atrophy visible by means of the 
ophthalmoscope is of great value. 

Fig. 104 shows a field of a case of homonymous 
hemianopsia which occurred in a recent hemiplegic. The 
patient was referred to Dr. Reber's Clinic in the Poly- 
clinic Hospital by Dr. John Rhein, with a diagnosis of 
hemorrhage in the neighborhood of the optic thalamus. 
This area was suggested by Dr. Rhein as the probable 
seat of the lesion because of the marked pain in the 
paralyzed extremities. The condition of the nerve head 
in this case is doubtful, but fields are conclusive of 
disease in the neighborhood of the optic thalamus and 
probably a little above, involving the internal capsule. 
A similar case under my care shows the same 
phenomena, a left-sided hemiplegia preceded by left 
hemianesthesia, left homonymous hemianopsia and 
conjugate deviation of the eyes to the right, with 
marked pain in both arm and leg. Optic atrophy is 
not visible by means of the ophthalmoscope. The 
lesion in this case is probably in the neighborhood 
of the internal capsule, involving the pulvinar. 

Of the primary optic centers, the external geniculate 
body is more directly concerned with the papillomacular 
bundle, while visual fibers pass also to the anterior 
corpora quadrigemina and pulvinar. The latter nucleus 
is the one which frequently is the seat of disease in 
hemiplegia of middle and late adult life, and hemian- 



180 SPECIAL PATHOLOGY OF FIELDS 

opsia is therefore observed more frequently in disease 
of this nucleus than either the external geniculate 
body or the anterior corpora quadrigemina. The 
reasons for involvement of the optic thalamus more 
frequently than the other basal nuclei are, (i) its 
proximity to the internal capsule, an area which is 
often the seat of hemorrhage, and (2) because of its 
size. The pregeniculate and quadrigeminal bodies 
are very small. Other concomitant symptoms of a 
hemianopsia in this region are hemiparesis, or hemi- 
plegia, hemianesthesia, hemichoreiform and athetoid 
manifestations, etc. If the external geniculate body 
alone were diseased, a crossed central amblyopia 
should be the characteristic symptom, as the papillo- 
macular bundle passes into this nucleus. 

Crossed Amblyopia. — Amblyopia, a symptom which 
is a frequently observed temporary phenomenon of 
commissural disease, and occasionally the beginning 
of permanent scotomata, is a more constant symptom 
in disease of the internal capsule, although not so 
frequently observed here as in disease of the optic 
radiations and the region of the calcarine fissure. In 
the internal capsule and throughout the optic radiations 
it is rather distinctive in type. After the onset of the 
central amblyopia which is bilateral and complete, 
there is a partial restoration of the halves of central 
vision which are represented by the macular centers 
on the opposite side of the lesion. In other words, 
the amblyopia becomes a hemianopic amblyopia of 
the homonymous type. This symptom, however, is 
more constantly observed in disease of the expansions 
of the optic radiations. Its presence argues for a 
separate pathway for the papillomacular bundle from 
the macula to the brain cortex. 

It is interesting to note that in the cases reported, 
central vision may be good for distance, but the defect 



FIELDS IN DISEASE OF THE OPTIC TRACTS 181 

is manifest at the near point. This is especially true 
when the hemianopic scotomata are to the right. (See 
Overshot Fields.) Wilbrand has pointed out that in 
reading, the minute details of the letters are neces- 
sary, whereas distant vision may be maintained with 
considerable central defect. 

Posey's case, recently reported, 1 is of great interest 
in this connection. Briefly, the history of the case is 
as follows: A man, aged fifty-six years, a victim of 
rheumatoid arthritis, suffered from sudden confusion 
of mind, dizziness, and disturbed speech. These symp- 




Fig. 105. — Crossed hemiamblyopia. (Posey.) 

toms cleared away after several days, when the fields 
in Fig. 105 were taken. Form fields remained normal* 
but small absolute paracentral scotomata to the left 
of the maculae remained, and persisted until the 
patient's death from apoplexy a year later. As in 
other cases, the maculae were probably totally involved 
at first, but his mental condition prevented the 
demonstration of the same perimetrically. After his 
mentality became normal, the scotomata were homony- 



1 Some Unusual Changes in the Visual Field, Journal of the American 
Medical Association, May 8, 1915, lxiv. 



182 SPECIAL PATHOLOGY OF FIELDS 

mous in type. These fields are remarkable, as one 
rarely can demonstrate perimetrically the presence of 
central hemiamblyopia of the homonymous type. 

DISEASE OF THE OPTIC RADIATIONS. 

The essential differences between the hemianopsia 
just under discussion and that occurring in lesions 
above the basal nuclei, are twofold: (i) atrophy is 
not in evidence in the nerve head; and (2) instead of 
pure types of hemianopsia, the field lesions take the 
form of irregular anopsias with a tendency finally 
to total loss of half-vision. Lesions in the optic 
radiations and calcarine cortex have been followed by 
atrophy of the basal nuclei, but atrophy has not been 
recognized in the nerve head. At all events, if it ever 
does occur, it is too infrequent to be of localizing 
value, or has been caused by coincident choked disc, 
which is quite common in disease of this region. The 
presence of choked disc is to be looked for in tumor 
formation, especially of the cerebellum and the posterior 
lobes of the cerebrum. Its presence is a factor in 
obscuring clear types of homonymous half- vision. 
There are other reasons, however, for the peculiar 
form of the anopsias to be noted in disease of this 
region. The small bundle of nerve fibers of the visual 
tract here expand into a fan-shaped fasciculus known 
as the optic radiations. For the most part these 
fibers are distributed along the calcarine fissure on the 
mesial surface of the cuneus — the higher visual centers. 
Others pass on to the psychic centers in the region of 
the angular gyrus, on the outer surface of the occipital 
lobe, and other fibers probably pass to the fore- and 
midbrain. With this wide distribution, therefore, parts 
of the optic radiations may become involved without 
entirely cutting off communication with all of the 
higher and psychic visual brain centers. 



DISEASE OF THE OPTIC RADIATIONS 183 

Color Anopsias. — Color anopsias are a frequent 
phenomenon and quadrant anopsias for color or for 




Fig. 106. — Diagram showing field changes in lesions of different parts of 
visual path. (After Mills.) 

form and color are commonly observed. Hemi- 
achromatopsia may be central or complete. In central 



184 SPECIAL PATHOLOGY OF FIELDS 

achromatopsia there is inability to recognize color in 
the macular area, whereas color perception may be 
preserved in the balance of the field. In complete 
achromatopsia of the homonymous type, color per- 
ception will be lost throughout the half-field. Color 
anopsias may be partial or complete as to the colors 
involved. For example — but one color may be lost, a 
case of red or green-blindness, etc., or a combination 
of colors may be lost, such as red-green-blindness. 
The possibility of these partial forms of achromatopsia 
is due to the presence of separate centers for the 
primary colors of the spectrum. Instead of complete 
achromatopsia, the patients may suffer from difficulty 
in deciding upon the color — dyschromatopsia — or a 
confusion of colors. One should also differentiate 
between the inability of the patient to see the colors 
and color amnesia — inability to name the colors which 
the patient may recognize and perceive correctly. 

Location of Higher Centers. — Munk, in his 
experiments on dogs and monkeys, came to the 
conclusion that the higher visual centers in these 
animals were arranged along the calcarine fissure 
very definitely. Along the inferior part of the fissure 
he found the higher centers which represent the inferior 
quadrants of the retinae, and along the upper part 
of the fissure the higher centers of the upper quadrants 
of the retinae. The classic case of Hun, so frequently 
quoted, does not confirm these observations of Munk. 
In Hun's case of left inferior quadrant anopsia, the 
lesion at autopsy was found in the lower half of the 
right cuneus. The brain in this case was not subjected 
to microscopic study, and it therefore is not of so great 
value in locating the half-visual centers as a case 
reported by Beevor and Collier {Brain, 1904, p. 153). 
The only nervous symptom of this case was blindness 
of the left upper quadrants, of which the patient 



DISEASE OF THE OPTIC RADIATIONS 



185 



was not conscious but was elicited by careful perimetric 
study. The maculae were intact. The condition 
continued about the same for tw r o years, when his 




Fig. 107. — Hun's case of quadrant anopsia. 

vision became worse; he became confused mentally, 
had convulsions and died suddenly. The gross autopsy 
findings showed an occlusive lesion of the right poste- 
rior calcarine artery which caused destruction of the 




Fig. 108. — Left superior quadrant anopsia. Case of Beevor and Collier. 

inferior third of the cuneus including all of the cortex 
above and below the calcarine fissure with the exception 
of a small point anteriorly. Careful microscopic study 



186 



SPECIAL PATHOLOGY OF FIELDS 



was made of the entire area and the lesion was found 
to be limited entirely to the cortex and the optic 
radiations were not involved. As the upper two- thirds 
of the cuneus were not diseased, the authors conclude 
that this area must represent the inferior quadrants 
which were intact, and the lower third including the 
lower and upper lips of the calcarine fissure represented 
the upper quadrants. 

So far as I have been able to learn, this is the only 
case subjected to careful gross and microscopic study 
which definitely throws light on the location of the 




Fig. 109. — Incomplete hemianopsia. (Posey.) 

higher visual centers. Other cases of quadrant anopsia 
have been reported, but all have failed of confirmation 
either by gross postmortem examination or more par- 
ticularly by microscopic study. The clinical reports, 
however, of a number of cases are of interest. In the 
Journal of the American Medical Association, May 8, 
191 5, Posey reports a case of "Permanent Quadrant 
and Hemianopic Losses following So-called 'Migrain- 
ous Attack.' " A woman, aged forty-six years, awoke 
with a headache and blurred vision which she attrib- 
uted to a bilious attack. Perimetric study resulted in 
the fields shown in Fig. 109. Central vision escaped. 



DISEASE OF THE OPTIC RADIATIONS 



is: 



The fields remained the same up to the time of the 
report. Posey ascribes the cause to a hemorrhage or 
thrombosis following prolonged spasm of an artery in 
the region of the cuneus. 

Weymann's case 1 is also of interest. The case was 
one of lues in an adult. Right hemiplegia following 
sudden unconsciousness was accompanied by a left 
superior quadrant homonymous anopsia and right 
inferior quadrant anopsia homonymous in character. 

Some investigators have located the higher visual 
centers for the maculae in the forward part of the cal- 




Fig. 110. — Left superior quadrant anopsia and right inferior quadrant 
anopsia. Weymann's case. Lesion in each cuneus. 

carine fissure. Others have located these centers in 
the angular gyrus, and another group of investigators 
believe that there are two macular centers in the brain — 
namely, one for distinct central vision in the forward 
part of the calcarine fissure, and a concept center in 
the region of the angular gyrus. Each group of investi- 
gators has produced evidence which seems to them 
at least to substantiate their claims. Many difficul- 
ties, however, are encountered in sharply limiting the 
lesions in experimental study and in pathologic research 

1 American Journal of Ophthalmology, October, 1894. 



188 SPECIAL PATHOLOGY OF FIELDS 

to each of these centers without involving connecting 
fibers, so that exact conclusions can hardly be drawn 
from the clinical materials at hand. There can, 
however, be no doubt of the existence of a cortical 
center for the papillomacular bundle, and the pre- 
ponderance of the evidence is in favor of the forward 
part of the calcarine fissure as its location. The case 
reported by Beevor and Collier particularly throws 
some doubt upon the location of the center in the 
anterior end of the calcarine fissure, as this area was 
almost totally involved but the macula remained 
intact. Mills 1 subscribes to this view, although he 
admits the presence of a lower cerebral and a higher 
or psychic center, as quite probable. In other words, 
he thinks "a strictly limited lesion of the calcarine 
cortex on the one hand, and of the angular region on 
the other, may cause blindness in half of the macular 
field of the corresponding side. " He, however, believes 
that the "half-macular representation is not so strictly 
defined by the vertical dividing line as in the peripheral 
retinal representation," and that "the macular center 
of one side is more or less representative of the macular 
fields of both sides." At all events, amblyopia is a 
characteristic symptom of lesions in the posterior 
part of the occipital lobe. Although complete at first, 
it soon becomes a partial or hemianopic amblyopia, 
homonymous in type. 

Most characteristic, therefore, of the perimetric 
findings in disease of the optic radiations and the 
posterior part of the occipital lobe are amblyopia, 
which tends to become hemianopic and homonymous, 
color and form anopsias, symmetric in both eyes but 
bizarre in outline and formation. Rarely, bilateral 
lesions may produce bilateral blindness following 
heterogeneous types of anopsias. 

1 The Eye and Nervous System, by Posey and Spiller. 



DISEASE OF THE OPTIC RADIATIONS 189 

An associated symptom in these cerebral types of 
anopsias, and helpful in locating the lesion, is the 
multitudinous variety of the concept center disturb- 
ance, known as mind-blindness. This leads us into the 
domain of the neurologist, but it is a subject not 
without interest to the ophthalmologist. Upon the 
presence or absence of mind-blindness and its particular 
character when present, together with the character 
of the accompanying anopsia, will depend the exact 
seat of the lesion, whether in the angular cortex, the 
calcarine fissure, or in the intracerebral structure con- 
necting these centers. 

The role of the perimeter, therefore, when pains- 
takingly and scientifically applied, becomes so impor- 
tant that in many instances it is the sine qua non of 
careful localizing diagnosis. 



PART VI. 

FIELDS IN FUNCTIONAL NERVOUS DISEASES. 

Clinically, it is at times a difficult matter to 
classify cases of functional nervous disease, because 
of dovetailing and overlapping of symptoms. A careful 
analysis, however, will usually enable the clinician to 
group his cases in one of three divisions — hysteria, 
neurasthenia and the traumatic neuroses. In most 
instances a combination of symptoms will be found, 
and by a careful weighing of the evidence the case 
can be properly classified by a preponderance of 
symptoms. 

This classification can, moreover, be further 
simplified by including the traumatic neuroses either 
under the head of hysteria or neurasthenia. A final 
analysis of these neuroses will clearly show that the 
symptom-complex of a given case is for the most 
part hysteria, and less frequently neurasthenia. Trau- 
matic hysteria differs very little from hysteria of the 
usual etiology, and the same is true of traumatic 
neurasthenia. It is unwise, therefore, to create a 
third group of functional nervous diseases because of 
the peculiar etiology. Insofar as the eye phenomena 
are concerned, and especially the perimetric findings, 
I know of no symptoms which these cases do not share 
with those who suffer from true hysteria and true 
neurasthenia. In fact, they are essentially the victims 
of hysteria with neurasthenic symptoms added. We 
will therefore discuss the fields in functional nervous 
disease under Hysteria and Neurasthenia. 



HYSTERIA 191 

A discussion of the general symptoms of these two 
diseases may be thought not to be germane to the 
subject of perimetry. A mere statement of perimetric 
facts, however, without a clear conception of the 
conditions which have given rise to the symptoms will 
be of little value in placing the proper interpretation 
upon them. In fact, a clear conception of the relation 
of cause and effect in these phenomena will reduce the 
perimetric deviations from the normal to a small 
group of distinctive types with slight variations. 

Hysteria. — Clinically, it is comparatively easy to 
differentiate between pure types of hysteria and 
neurasthenia, and only the borderline cases become 
confusing. What is the essential element which is 
active in producing the hysteric phenomena? However 
numerous the manifestations of hysteria may be, 
and of whatever character, the underlying principle 
is that of inhibition, and a careful analysis of each 
symptom will demonstrate this fact. The means by 
which each patient arrives at the stage when the disease 
may be called hysteria will differ widely in each 
individual, but the ultimate product of analysis will 
be the condition of inhibition — a condition in which 
the patient is so influenced by environment, in its 
broadest sense, that the personal will-power has been 
lost, or is so feebly active as to be unable to respond 
normally to normal stimuli. A second factor is added 
to the enfeebled will-power, namely, either failure 
of the normal sensory end-organs to receive impressions, 
or failure of the end-organs to produce the normal re- 
sult of their stimulation upon the consciousness of the 
patient. It is alleged by Binet and Janet, as quoted 
by de Schweinitz, that patients suffering from hysterical 
amaurosis, when placed under hypnotic influence, 
can recall what they saw before the hypnotic state 
was induced, during the amaurotic period. This 



192 FIELDS IN FUNCTIONAL NERVOUS DISEASES 

would tend to argue for the integrity of the sensory 
end-organs. It is unnecessary- at this time to analyze 
the general symptoms of hysteria to illustrate this 
conception of the disease. Every 7 physician will be 
able to recall from his practical experience instances 
to which he can apply this principle. It is but pertinent 
to add that the therapeutic measures which have 
effected cures or have relieved these patients, have 
been in the line of suggestive therapeutics. 

It is interesting to draw a brief analogy between 
the general symptoms and the eye symptoms of 
hysteria. Anesthesia of the skin finds its analogue 
in the eye in the hysteric amblyopia and amaurosis. 
Not only is this condition bilateral, but in hemianes- 
thesia of the body the amblyopia or amaurosis may 
be unilateral. Local areas of skin anesthesia may be 
represented in the retina in the form of scotomata. 
Muscular palsy, so frequently observed as hemiplegia, 
monoplegia, etc., occurs in the eye in external or 
internal, complete or partial, ophthalmoplegia. 
Paralysis of the sphincter muscles of the bladder, or 
tonic spasm of the sphincters, also finds its analogue 
in the eye in ptosis, tonic blepharospasm, etc. Painful 
points, or hyperesthesia, of the skin, are similarly 
represented in the eye in photophobia, lacrimation, 
etc. 

The retina is a sensory end-organ which is especially 
well adapted to illustrate the vagaries of the symptom- 
complex of hysteria, and the symptoms found are as 
varied as the complexity of the visual act would lead 
one to expect. Three types of changes, however, 
are especially characteristic: (i) concentric contraction 
of fields, with or without central amblyopia; (2) 
tubular fields; (3) reversal of color fields. 

Amaurosis need not be considered here, because 
when the eye is blind to all forms of stimulation the 



HYSTERIA 193 

form and color fields cannot be elicited. It is well 
to emphasize the fact that no part of the retina enjoys 
immunity in hysteria, and that any variation of the 
field observed in organic disease of the visual tract 
may be found in hysteric disease. This latter observa- 
tion is not generally accepted, but my own personal 
experience has been that the possibilities of field changes 
in hysteria are only limited, with a few exceptions, 
by the patient's knowledge. It would be rare indeed 
to find a condition of homonymous hemiamblyopia 
limited to central vision, as it is exceptionally rare 
in organic disease. Homonymous hemianopsia has 
been observed, and other irregularities have been 
developed on the perimeter which follow very closely 
similar phenomena observed in organic disease. From 
these facts just set forth, one might be led to believe 
that hysteric perimetric phenomena after all are only 
a simulated condition and the result of wilful deception 
on the part of the patient. They are not the result 
of malingering or wilful deception but are the result 
purely of inhibition. The amaurosis of hysteria, for 
instance, may be relieved at times by the placing of 
a plain lens before the amaurotic eye, with the sugges- 
tion of possible relief of the blindness, especially 
when this is done in a systematic and convincing 
manner. No amount of suggestive therapeutics would 
cause the malingerer to see, and nothing short of 
absolute detection of the fraud by a trick would 
bring back the sight of one who wilfully deceives. 

Concentric Contraction. — Most characteristic, and 
probably most frequently observed, is the circular 
shape of the field contracted to various degrees. 
Contraction almost to the center will often be found. 
What I have usually observed is a form and color 
field of almost equal size. In other instances, color 

fields may be contracted in their usual order and in 
13 



194 FIELDS IN FUNCTIONAL NERVOUS DISEASES 

proportion to the reduction of the fields as observed 
in optic neuritis. The rule, however, is atypical of 
organic disease, although resembling it. Large re- 
entering angles are rarely found. Given a normal 
eye-ground with form and color fields contracted 
and of approximately equal size, the diagnosis 
is presumably hysteria. This contraction may be 
associated with a central scotoma, or even an annular 
scotoma, instances of which have been reported in 
literature. 




Fig. 111. — Hysterical fields. Patient sixteen years of age. Concentric con- 
traction. Tubular fields and reversal of color fields. 



Tubular Fields. — If a doubt exists as to the genuine- 
ness of the hysterically contracted field, further proof 
w T ill be found in varying the distance between the 
patient and the blackboard or campimeter. Paren- 
thetically it may be added that the campimeter is 
the ideal instrument with which to measure this 
type of field. Under normal conditions the field will 
enlarge as the patient recedes from the blackboard. 
(See Fig. 42.) In hysteria, however, the same size 
field may be obtained at any distance, as shown in 
Fig. in — a symptom which tends to confirm the 
hysteric character of the first type of field mentioned. 



HYSTERIA 195 

This type is known as the tubular field. It occurs 
only in hysteria and in malingering. 

Reversal of Color Fields. — The third type of field 
which, in itself when carefully taken and analyzed, 
and in conjunction with one or both of the other forms 
mentioned, is characteristic of hysteria, is the field 
in which the order of colors is reversed. In this field 
the red may be smaller than the green, or as 
de Schweinitz believes, the red may be enlarged to 
reach beyond the blue — a condition possibly of hyper- 
sensitiveness to red. In all probability it is due as 
much to insensitiveness of the retina to the blue 
elements. Hyperesthesia of the skin is not unusual, 
and hyperesthesia of the retina to one or more of the 
colors is entirely within the range of possibility. 
However, the eye phenomena, for the most part, 
are manifestations of lowered sensibility, rather than 
hypersensibility. Furthermore, it is well to remember 
that in early chorioretinitis with questionable eye- 
ground change, contraction or defect of the blue field 
may be an early perimetric finding. In hysteric 
reversals, also, form fields may be approximately 
normal. When, therefore, the red-blue fields are 
reversed, and the first and second types of hysteric 
fields are absent, the evidence should be carefully 
weighed before classifying the field as functional. 
Instead of simple reversals of the colors, interlacing 
may be found. If such a field is obtained, it should 
be immediately retaken with special care as to the 
position of the patient's head. A slight shifting to 
one side may be responsible for this form of defect. 
It may, however, be a genuine hysteric manifestation. 
These are the types, therefore, which are especially 
characteristic of hysteria. Each one of the three may 
be present in the same patient, and if present would be 
strong evidence of the hysteric character of the disease. 



196 FIELDS IN FUNCTIONAL NERVOUS DISEASES 

Dyschromatopsia, Color Amblyopia. — Dyschromatop- 
sia, color amblyopia, and other forms of disturbance 
of the field may be found. They, however, are but 
variations of the types spoken of, and in themselves 
are not diagnostic. 

The literature on the occular evidences of hysteria, 
and especially perimetric changes, is voluminous, 
and almost every phase of change observed in organic 
disease has been reported in hysteria. Many of these 
symptoms are not distinctive. They should, however, 
receive due consideration, and because of their rarity 
be weighed in the balance all the more carefully. 

By some investigators the oscillating field is in- 
cluded in the hysterical phenomena. It is, however t 
a phenomenon more strictly neurasthenic, and will be 
discussed under Neurasthenia. 

Neurasthenia. — The. essential element in neuras- 
thenia is fatigue — mental and physical. The inability 
of the patient to concentrate and sustain thought, 
muscular asthenia, and its secondary -irritability, are 
a group of phenomena which make up the symptom- 
complex of neurasthenia. Unlike hysteria, this con- 
dition is usually the result of a long-drawn-out 
enervating process — a product of overwork or of the 
tension of certain forms of occupations and professions. 
The strong, therefore, because of their overestimated 
power of endurance, are as often the victims of neuras- 
thenia as those who have less stable nervous systems. 

The perimetric symptoms are no exception to the 
rule in this disease. They are similar in character 
to the general symptoms. Fatigue of the retina, 
probably of a nutritional character, and inability to 
concentrate in conscious mental acts, are the forces 
which bring about the perimetric changes. It so 
happens that many cases of pure neurasthenia become 
mixed in time with hysteria, and therefore the 



NEURASTHENIA 197 

perimetric findings may be composite. This fact will 
account for the rather complicated perimetric 
phenomena described in text-books and literature 
as of neurasthenic origin. If one should add to the 
manifold evidences of hysteria the elements of mental 
and physical tire, no end of composite phenomena 
would be the result. Essentially, in making a differ- 
entiation between hysteria and neurasthenia, in the 
field changes, I am in accord with von Reuss, who 
contends that constant visual field changes are hysteric 
and variable field changes are of neurasthenic origin. 
This expresses the dominating characteristics of the 
fields which harmonize best with our conception of 
hysteria and neurasthenia. 

It is doubtful whether fatigue alone of the retinal 
elements, due to faulty nutrition, or fatigue alone 
of the concept centers, will explain all of the field 
phenomena in neurasthenia. Evidence of retinal 
fatigue, as shown in the spiral field, does not account 
for the occasional lowering of central vision, which 
can only be explained by fatigue of the higher visual 
centers. 

Fields as Result of Fatigue. — In profound neurasthenia, 
if the form field, for example, is taken, beginning at 
the temporal side and continued indefinitely, a form 
field will be defined as illustrated in Fig. 43, known 
as the spiral field of von Reuss. This illustrates 
most graphically the element of fatigue. Unlike 
hysteria, it begins in the periphery, where the retinal 
elements should first show evidence of nutritional 
change, and gradually approaches the center. 

Wilbrand's exhaustion type of visual field is really 
an expression of the same phenomenon. He arrives 
at his conclusions in a slightly different manner. 
Beginning on the temporal side, the test object is 
slowly moved across the horizontal meridian and 



T98 FIELDS IN FUNCTIONAL NERVOUS DISEASES 

the points of entrance and exit of the test object 
are noted. The object is now passed slowly back and 




Fig. 112. — Wilbrand's exhaustion type of field. 

across the same meridian and the points of entrance 
and exit again noted. By continuing this process, 




Fig. 113. — Forster's method of taking exhaustion field. 



as in Fig. 112, these points approach nearer and nearer 
to the center. The test may be applied to any meridian. 



XEURASTHENIA 199 

It is not a special form of field but a convenient method 
of demonstrating retinal fatigue, if present. Another 
method of eliciting the evidence of fatigue is by Forster's 
method, which is illustrated in Fig. 113. The test 
object is passed from the temporal side to the nasal 
side, the point of entrance and exit being noted. The 
same measurements are made along another meridian, 
always from the temporal to the nasal side, until 
the field has been taken. If the process is now reversed, 
and the test object is passed from the nasal to the tem- 
poral side, the field as indicated above will appear. Of 
the methods mentioned, Wilbrand's is probably the quick- 
est and most satisfactory, although the spiral field shows 
best in a diagrammatic way the presence of fatigue. 
Concentric contraction to any marked extent is evi- 
dence of a probable hysteric complication. The same 
may be said of marked reduction in central vision, and 
of the presence of scotomata of any enduring character. 

Scheele's theory of a homonymous type of exhaus- 
tion field, i. e., exhaustion manifested in corresponding 
retinal halves, has not been substantiated. It could 
only be possible if the exhaustion phenomena originated 
in the cerebral cortex and were limited to one side. 

Oscillating Fields. — Wilbrand claims that under 
certain circumstances, instead of a progressive fatigue 
in passing the test object through any meridian, a 
field similar to that represented in Fig. 114 will appear. 
In other words, the test object will momentarily 
disappear, only to reappear again in several points 
in the same meridian. As neurasthenic patients have 
difficulty in reading because of the momentary blurring 
and running together of words and letters, this type of 
field is within the range of possibility. I have never 
been able to elicit a field of this sort in any of the 
neurasthenic cases which I have examined, although 
occasionally a patient will speak of momentary disap- 



200 FIELDS IN FUNCTIONAL NERVOUS DISEASES 

pearance of the test object. It is probable that it is 
an exceedingly rare phenomenon. 

The fields which are obtained in neurasthenia are 
essentially fatigue fields. They are not, therefore, 
peculiar to neurasthenia, but are found in modified 
forms in other diseases. It is, however, the element 
of fatigue which is exemplified in them, and in no 
condition is this element so marked as in neurasthenia. 




Fig. 114. — Wilbrand's oscillating field. (Norris and Oliver.) Courtesy of 
J. B. Lippincott & Co.) 



Practically nothing has been said of the color fields 
in neurasthenia. Colors behave similarly to the 
white object, and the same phenomena described for 
form may be elicited with any of the primary colors. 

Ophthalmic Migraine or Scintillating Scotoma 
of Migraine. — Migraine is a neurosis which is not 
unlike epilepsy in its symptomatology and etiology. 
Heredity, directly or indirectly, is the most important 
etiologic factor. It resembles epilepsy in symptoma- 
tology: (i) in the presence of an aura in a consider- 
able number of cases; (2) in its explosive character; 
(3) in the inhibition which follows the overstimulation 



OPHTHALMIC MIGRAINE 201 

of the gray matter; (4) in the irregularity of the 
recurrences of the attacks. 

Entoptic studies made by the patient are of some 
value in this disease because it usually occurs in an 
intelligent class of people. Men and women known 
for their scholarship frequently are the victims, and 
their entoptic observations are for the most part 
dependable. 

Two types of the ophthalmic variety are recognized : 
(1) the form accompanied or followed by distinct 
scotomata; (2) a milder type of disease known 
ordinarily as "sick headache. " 

When typical in onset the first variety is ushered 
in by dazzling or shimmering lights usually situated 
to the right or left or occasionally covering the greater 
part of the field. What is even more characteristic 
is what is known as the fortification spectrum. The 
dazzling lights assume the form of a crescent or comet 
and zigzag back and forth in the field for an appreciable 
time. In some instances the fortification spectra are 
highly colored. One patient described the peaks as of 
gold and the bases of rose. In nearly all forms the 
periphery is clear and the spectra are to the right or 
left of the center. These periods of overstimulation 
are soon followed by a period of exhaustion and the 
shimmering lights give way to dark areas in the field 
situated either to the right or left of the center — 
scotomata, homonymous in character. 

Less frequently the attack is ushered in by the 
appearance in the field of a dark spot which gradually 
enlarges, the center clearing as the periphery enlarges. 
At times the dark spot becomes luminous in the 
periphery. At other times patients have hallucinations 
in these areas. Posey reports the case of a woman who 
saw a bull's eye in the center of the dark area. At 
times the dark area which follows the scintillations 



202 FIELDS IN FUNCTIONAL NERVOUS DISEASES 

covers the entire half-field of vision, producing right 
or left homonymous hemianopsia. In other instances 
the spectra are replaced by quadrant defects in the 
field, corresponding retinal quadrants being affected. 
In any variety the period of overstimulation is brief 
and the phenomenon of scotomata is accompanied 
by a hemicrania or a nervous form of sick headache. 
The hemianopic scotomata are observed by the patient 
as positively blind areas and perimetric studies will 
demonstrate their presence if the examination is made 
before the phenomenon has disappeared. In this form 
of scotoma the patient may refer the blind area to 
one eye because it occupies the right or left of the 
field. It, however, is a bilateral condition, hemianopic 
in character. 

Perhaps a more frequently observed type of scintil- 
lating scotoma is that known as a pyrotechnic display 
of lights. Shimmering lights of all colors will dazzle 
before the patient's eyes for a moment, and immediately 
there will follow indistinct dark areas which rapidly 
disappear. The phenomenon is similar in character 
to the fortification spectrum, but as a rule it represents 
a milder type of disease. Headache follows as in the 
severer form of the disease. The headache is of the 
hemicranic type. 

Perimetric studies of the latter variety rarely show 
scotomata. A contraction of the form and color 
fields can usually be demonstrated. In the hemianopic 
variety, however, if studies are made early the scoto- 
matous areas can be clearly defined and the fields on 
the unaffected side may show contraction. 

In Fig. 115 the fields of a patient who suffered 
repeatedly from attacks of migraine with scintillating 
scotomata are shown. Inequality in the size of the 
form fields in this case is due to a condition of 
anisometropia. 



OPHTHALMIC MIGRAINE. 



203 



In Fig. 116 are the fields of the same patient taken 
within a half-hour after the onset of an attack of 
migraine. Although no scotomata were found in any 




Fig. 115. — Scintillating scotoma of migraine between attacks. 

part of the field, the hemianopic tendency is well 
illustrated. Not only are the fields hemianopic, but 
there is a marked reduction in both form and color 
fields. I had the opportunity of studying this case 




Fig. 116. — Scintillating scotoma of migraine. Same case as in Fig. 115, 
one-half hour after attack. 

upon a number of occasions shortly after an attack, 
and invariably the fields assumed the form shown in 
the last figure. The hemianopic tendency was so 



204 FIELDS IN FUNCTIONAL NERVOUS DISEASES 

characteristic that the patient described the left 
homonymous form of hemianopsia typically, the seeing 
half and the blind half being separated by a sharp 
dividing line a little to the left of the center. 

Dr. William Zentmayer 1 reported an interesting 
case of ring scotoma in a case of migraine. It is difficult 
to explain the formation of the complete ring in the 
right eye, as the irritation or process, whatever it may 
be which gives rise to the eye phenomena, has its 
origin in the cuneiform body and therefore should be 
hemianopic. It is interesting to note, however, that 




Fig. 117. — Ring scotoma of migraine. (Dr. William Zentmayer.) 

the author reports typical hemianopic defects in the 
fields after the first few seizures. 

Because of the fleeting character of the scintillations 
one rarely has the opportunity of studying the field 
immediately after an attack. The entoptic study 
by the patient, however, is usually dependable, and 
many of these patients can give graphic descriptions 
of the color phenomenon, and can make accurate 
drawings of the scotoma which subsequently appear. 

The perimetric phenomena of migraine definitely 
locate the seat of the ophthalmic variety in the 

1 Annals of Ophthalmology, xxi, 279. 



OPHTHALMIC MIGRAINE. 



205 



visual cortex and most probably in the calcarine 
fissure. In a few instances the earliest premonitory 
sign is a macular scotoma which gradually enlarges 
but always remains hemianopic. In other instances 
the upper or lower corresponding quadrants are 
involved but at all times homonymous. These facts 
strengthen our belief that the seat of the disease is 
in the calcarine cortex. The immediate process 
probably is of circulatory origin, as no constant lesion 
has been found in patients suffering from this neurosis. 




90 SO 




Fig. 118. — Quadrant anopsia of migraine. (Dr. Wm. Campbell Posey.) 

A number of cases of quadrant and hemianopic 
scotomata have persisted for varying periods and some 
have remained permanently hemianopic. Hoeflmayer, 
according to Posey, noted permanent hemianopsia 
in a woman, aged fifty-seven years, for one month 
after a migrainous attack. Charcot reported a 
case of permanant hemianopsia following an attack 
of migraine. Noyes's case had frequent attacks of 
migraine for ten years. Finally, in a severe attack, 
left lateral hemianopsia followed, with a contraction 
of the nasal field of the left eye. At autopsy a clot 
was found in the right cuneus. Other cases of a similar 
character have appeared in literature from time to 



206 FIELDS IN FUNCTIONAL NERVOUS DISEASES 



time. It may be assumed, therefore, that migraine 
in all probability is due to a spasm of small vessels in 
the cuneus, and that in those cases in which the 
fields have remained permanently effected, the oft- 
repeated attacks of migraine have eventually resulted 
in permanent occlusion of the vessel with subsequent 
softening of the brain tissue. The functional disease 
has given way to an organic lesion. 



APPENDIX. 

In addition to the use of the perimeter incident 
to the study of visual fields, the perimeter, or its 
modifications, may be employed (i) to study the field 
of monocular fixation; (2) to measure the degree of 
strabismus; (3) to study and chart diplopia, and (4) to 
locate foreign bodies. 




Fig. 119. — Field of monocular fixation of the right eye recorded upon an 
ordinary perimetric chart. 



The Field of Monocular Fixation. — The field 
of monocular fixation may be measured approximately 
either on the perimeter or campimeter. The patient 
is seated before the perimeter or campimeter as in 
the taking of the visual fields, with one eye covered, 
the eye under examination fixing upon the center of the 
instrument. A test object of fine points definitely 
separated, or as suggested by Duane, fine parallel 
lines, is slowly moved from the point of fixation on 
the arm of the perimeter or on the campimeter, and the 



208 APPENDIX 

patient is instructed to follow the test object with the 
eye until the parallel lines become blurred or indis- 
tinguishable. This point will mark the extreme rotation 
of the eye in that particular meridian. Eight points 
of rotation should be measured — out, in, up, down, up 
and in, down and in, up and out, and down and out. 
A field of fixation may in this manner be completed, 
as suggested by Landolt and others, and for this pur- 
pose ordinary perimetric charts may be employed. 

Fig. 119 illustrates the normal field of the right 
eye recorded on an ordinary perimetric chart, the 
measurements being according to Landolt. Duane's 
measurements on his tangent curtain are: 

Outward rotation 51 degrees 

Inward rotation 53 " 

Upward rotation 43 " 

Downward rotation 63 " 

These measurements compare favorably with those 
taken by Stevens and also Reber on the tropometer. 
Stevens's figuresare: 

Outward rotation 50 degrees 

Inward rotation 55 " 

Upward rotation S3 " 

Downward rotation 50 " 

Degree of Strabismus. — The amount of deviation 
in strabismus may be approximately obtained on the 
perimeter. The patient is seated before the perimeter 
in a dark room and is asked to fix his non-squinting 
eye, both eyes being uncovered. A small electric 
light is now passed along the inside of the arc until 
the corneal reflex on the squinting eye falls upon the 
center of the pupil of the deviating eye, and the degree 
of squint is noted on the arm of the perimeter. In 
cases of convergent squint the light is moved to the 
side opposite the squinting eye, and in divergent 
squint, in the direction of the squinting eye. The 



LOCATION OF FOREIGN BODIES 209 

results thus obtained will compare favorably with other 
methods of measuring deviations. 

Diplopia. — For the purpose of determining and 
charting diplopia, the campimeter is well adapted. 
A red glass may be placed over one eye, the patient 
being seated before the campimeter in the usual 
manner. An electric lamp is now moved to the right 
and left, up and down, up and in, down and in, up and 
out, and down and out. One object being red and the 
other yellow will enable the patient to determine 
readily the direction of the diplopia, the direction in 
which the diplopia is greatest, and the relation of the 
true to the false image. 

Location of Foreign Bodies. — Foreign bodies in 
the eyeball have been located with sufficient accuracy 
to guide the operator in their removal by locating the 
resulting scotomata on a perimeter or blackboard. 
Dr. Charles A. Oliver many years ago was fortunate 
enough to locate a foreign body in this manner. More 
recently two cases of cysticercus have been located 
so accurately as to allow the operator to remove them 
with wonderful precision. In La Clinigue Ophthal- 
mologique, July, 19 14, p. 468, Dupuy-Dutemps reported 
a cysticercus located subretinally. The position of 
the cysticercus was located by means of the scotometer. 
Extraction was done under cocaine by a meridional 
scleral incision. J. Hirschberg, 1 Berlin, also reported 
the extraction of a cysticercus from the vitreous which 
was located by the defect in the visual field. The special 
advantage of this means of locating foreign bodies 
lies in the fact that in selected cases the perimeter 
may enable the surgeon to locate a foreign body, non- 
metallic and unsuitable for x-ray localization. 

1 Centralbl. f. Prakt., July and August, 1914, p. 192. 



14 



BIBLIOGRAPHY. 

In addition to the standard text-books and current 
literature to which reference has been made in the 
text, the following bibliography, which the author has 
consulted, is added for the benefit of those who are 
interested in the various problems which perimetry 
presents. 

An effort has been made to limit the included titles 
for the most part to monographs and papers which 
are the result of individual or collective study of large 
numbers of cases. Many valuable papers have neces- 
sarily been omitted because they either cover the 
same ground as those which are included in the list, 
or present reports of cases of typical perimetric 
phenomena. 

The reader will note that many monographs and 
papers are accompanied by a bibliography, and such 
articles are marked by a double star. As reference is 
made in each bibliography to all the important papers 
bearing on the subject for many years past, the author 
has confined his bibliography largely to the last decade, 
during which time the practice of perimetry has made 
great progress and the contributions have been many 
and of great value. 

An effort has been made to classify all articles for a 
more ready reference. This, however, is a difficult 
matter, as many of the papers may with equal facility 
and appropriateness be included in one or more of the 
several subheadings. 



BIBLIOGRAPHY 211 



NORMAL FIELDS. 

Bull, Ole. Perimetric. 

Bass, Karl. Das Gesichtfeld. 

Wilbrand. Norris and Oliver's System of Diseases of the Eye, ii. 

de Schweinitz. Diseases of the Eye. 

Weeks. Diseases of the Eye. 

Fuchs. Text-book of Ophthalmology. 

Parsons. Diseases of the Eye. 

Mirto. Binocular Visual Field in the Two Sexes and in Epileptics, Klin. 
Monatsbl. f. Augenh., April, 1910, p. 518. 

Roemer. Text -book of Ophthalmology. 

Campbell, H. Neurology of Visual System, Med. Press and Circ, 
December 11, 1912. 

Calderaro. Study of Indirect Vision, Clin. Ocul., xii, 1109. 

Day, L. M. Effect of Illumination on Peripheral Vision, Amer. Jour. 
Psychol., xxiii, 533. 

Milutin. Law of Identical Visual Direction, Ztschr. f. Biol., Munch, u. 
Berlin, lx, 41. 

• Paird, J. W. Phenomena of Indirect Color Vision, Psychol. Rev., 
Princeton, xli, 70. 

Ferree, C. E. Vision, Peripheral and Foveal, Psychol. Bull., Princeton, 
ii, 87. 

Tscherning. Physiologic Optics. 

Swanzy. Diseases of the Eye. 

METHODS OF STUDYING THE FIELD. 

Sinclair, A. H. H. Bjerrum's Method of Testing Field of Vision; Clinical 
Advantages and Value in Glaucoma, Trans. Ophth. Soc. of U. K., xxv. 

Sym and Sinclair. Apparatus for Bjerrum's Test, Ophth. Review, May 20, 
1906. 

Duane, A. Tangent Plane for Mapping Scotoma, Field of Vision and 
Double Images, Ophth. Rec, October, 1906. 

Auberet. New Form of Campimeter, Arch. d'Opht., November, 1906. 

Smith, P. Scotometer for Diagnosis of Glaucoma, Trans. Ophth. Soc. U. K., 
xxvi. 

Tomlinson. A New Perimeter, Trans. Fifteenth Internat. Med. Cong., 
Lisbon. 

Collin, R. Clinical Methods of Studying Color Sense, Ztschr. f. Augenh., 
April, 1906. 

Davis, F. A. Recent Improvements in Perimetry, Med. Rec, June 30, 
1906. 

Horne, L. Field of Fixation and Methods of Measuring It, Ann. of Ophth., 
April, 1906. 

Fortin, E. P. Entopic Examination of Vitreous, Rec. d'Opht., January, 
1907; Method of Examining Entoptically Retinal Circulation and Fovea, 
Comptes Rendus de la Societe de Biologie, March and June, 1907; Ophth. 
Review, August, 1907, p. 243. 



212 BIBLIOGRAPHY 

Auberet. New Model of Campimeter, Wchnschr. f. Therap. u. Hyg. des 
Auges, March 14 and 21, 1907. 

Sauvineau, C. Decimal Scale for Measurement of Chromatic Sense, 
Ann. d'Oculist, July, 1908. 

Holth, S. Apparatus for Early Detection of Central Color Scotoma, 
Narsk Magazine Laegevideuskaben, May, 1908; Diagnosis of Central Sco- 
toma for Colors: Three Simultaneous Identical Tests, Ann. d'Oculist, Sep- 
tember, 1908. 

Fortin, E. P. Examination of Central Vision, Recueil d'Opht., February, 
1908. 

Bardsley, P. C. New Form of Scotometer, Trans. Ophth. Soc. U. K., 
xxviii. 

Micoci. Limits of Visual Field for White and Colored Objects, Nippon 
Gank. Zasshi, January, 1908. 

Smith, P. An Improved Perimeter, Trans. Ophth. Soc. U. K., xxix, 52. 

Adams, P. H. A New Perimeter, Ophthalmoscope, 1909, p. 80. 

Tomlinson, J. H. Scotomagraph with Binocular Fixation, Brit. Med. 
Jour., 1909, ii, 985. 

Moretti, E. Scotometer for Central Scotoma, Ann. di Ottal., xxxiii 
Fase 4. 

Armaignac, H. Measurement and Notation of Visual Field, Arch. d'Opht., 
1909, p. 593; Ophthalmoscope, 1909, p. 841. 

Wolfflin. Electric Light Apparatus for Taking Binocular Fields, Klin. 
Monatsbl. f. Augenh., February 19, 1910, p. 194; Ann. of Ophth., xix, 544. 

Tomlinson, J. H. Scotomagraph with Stereoscope Fixation, Trans. 
Ophth. Soc. U. K., xxx, 111. 

Nagel. Standardization and Choice of Color Tests, Ann. d'Ocul., cxliii, 
477. 
**Evans, J. J. Field of Vision (Bibl.), Ophthalmoscope, 1912, ix, 698. 

Haycroft, J. B. Method of Mapping Blind Spot of Retina, Lancet, 
August, 1911, p. 518. 

Hird, R. B. Scotometer for Measuring Central Scotoma, Ophthalmoscope, 
1912, x, 142. 

Holloway, T. B. A Bjerrum Stick, Amer. Ophth. Soc, xii, 966. 

Syndacker, E. T. Useful Addition to Test Chart, Arch, of Ophth., xl, 149. 

Reber and McCool. Umbrella Perimeter, Sec. on Ophth., Coll. Phys., 
Phila., January 19, 1911; Ophthalmology, ix, 500. 

Walker, C. B. New Instruments for Measuring Visual Field Defects, 
Arch. f. Augenh., v, 42, 577; New Perimetric Instruments, Jour. Amer. Med. 
Assn., lxi, 277. 

**Black, N. M. Quantitative Method in Perimetry, Perimetric Apparatus 
(Bibl.), Ophth. Rec, xxxiii, 65. 

Onishi. Binocular Perimeter, Nippon Gank. Zasshi, February, 1914. 

Henderson, T. A Scotometer, Ophthalmoscope, xii, 279. 

Ronne, H. Taking Visual Fields, Klin. Monatsbl. f. Augenh., Hi, 554. 
**R6nne. Theory and Technique of Bjerrum's Method of Studying the 
Visual Field (Bibl.), Arch. f. Augenh., lxxviii, 284. 

Duane, A. The Tangent Curtain, Arch, of Ophth., xliii, 420-591. 

Holth. The Chords Perimeter, A Cheap Pocket Instrument for Taking 
Visual Fields, Klin. Monatsbl. f. Augenh, liii, 197. 



BIBLIOGRAPHY 213 

**Eppenstein, A. Perimetry in Paracentral Scotoma (Bibl.), Zeit. f. 
Augenh., xxxii, 16. 

Fridenberg, P. Clinical Defects in Measurements of Defects in Central 
Visual Field, New York Med. Jour., December 21, 1912, p. 1257. 

Charles, J. W. Convenient Form of Hoitz's Stereoscopic Chart for 
Investigation of Central Scotoma, Am. Jour. Ophth., xxx, 69. 

Oppenheimer, E. H. Disk for Perimetric Test, Vergl. Ztschr. f. Ophth., 
Optik. 1, p. 17. 

Hird, R. B. A Hand Perimeter, Ophthalmoscope, xi, 540. 
**Traquier, H. M. Quantitative Method in Perimetry: Perimetric Appa- 
ratus, Ophth. Rec, xxx, 65 (Bibl.). 

Hawthorne, C. O. Perimeter Charts, Lancet, May 9, 1914, p. 1325. 

Pearson, J. Illuminated Scotometer for Railway Color Test, Ophthalmo- 
scope, xii, 408. 

Dennis, D. N. Attachment for Taking Light Fields, Arch, of Ophth., xliii, 
624. 

Hefftner, F. Size of Object and Field of Vision, Graefe's Arch, of Ophth., 
lxxxix, 186. 

**Berling, E. Visual Fields Taken by Bjerrum's Method (Bibl.), Arch. f. 
Augenh., lxxviii, 152. 

Maddox, E. E. An improved Hat-pit for Visual Fields, Ophth. Rec, p. 
304. 

Nakamura. Use of Perimeter of Mizno, Nippon Gank. Zasshi, April, 1915. 

Peter, L. C. A New Hand Campimeter, Ophth. Rec, July, 1915. 

Peter, L. C. A Form and Color Test Object for Perimetric Work, Arch, 
of Ophth., xliv, 416. 

Asmus, E. Mechanical Improvement of Forster's Perimeter, Klin. Mon- 
atsbl. f. Augenh., liv, 516. 

Duane, A. Mapping of Scotomata, Arch, of Ophth., xliv, 487. 

Schiotz, H. New Self-registering Perimeter, Norsk. Mag. for Laegevid, 
lxxvi, 1108. 

Miles, G. H. Formation of Projected Visual Images by Intermittent 
Retinal Stimulation, Brit. Jour. Physiol., vii, 420. 

Reitsch, W. P. Technique for Estimation of Complete Homonymous 
Hemianopsia, Munch, med. Wchnschr., August 10, 1915, lxi. 

ANATOMY AND PHYSIOLOGY. 

Dean, G., and Usher, C. H. Course of Optic Nerve Fibers, Brain, xxiv, 
No. 103. 

**Gamble, W. E. Architecture of Cerebral Visual Apparatus (Bibl.), Ann. 
of Ophth., April, 1904. 

Parsons. The Neurology of Vision, Lancet, April 16, 1904. 
**Wilbrand and Saenger. Die Neurologie des Auges, iii, Part I. 

Fernald, G. M. Effect of Brightness of Background on Appearance of 
Color Stimuli in Peripheral Vision, Psychol. Rec, 1908, xx, 25. 
**Cross, F. R. Brain Structures Concerned in Vision (Bibl.), Lancet, 1909, 
ii, 1799. 

Bassalino. Course of Nerve Fibers in Optic Nerve and Chiasm, Arch. d. 
Ophth., xxx, 705. 



214 BIBLIOGRAPHY 

Lenz. Researches on Visual Center, Trans. XXXVI Ophthal. Cong., 
Heidelberg. 

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Barck, C. Focal Localization Along Visual Paths, Ann. of Ophth., xxiv, 37. 

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BLIND SPOT OF MARIOTTE. 

Kampherstein. Pathology and Pathogenesis of Choked Disc, Klin. 
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Contonnet. The Macular Region and the Prognosis of Myopia, Arch. 
d'Ophth., June, 1906. 

Ramsay, A. M., and Sutherland, A. W. Enlargement of Blind Spot with 
Congestion of Optic Disc, Ophth. Rec, January, 1906. 

Ovio, G. Observations on the Blind Spot of Mariotte, Ann. di Ottal, 
Nos. 1 and 2, Ophthalmology, July, 1907, p. 745. 

Ovio, G. Blind Spot of Mariotte and Irradiations,' Ztschr. f. Augenh., 
January, 1908, p. 77. 

Van der Hoeve, J. Enlargement of Blind Spot in Optic Nerve Involve- 
ment in Diseases of Posterior Accessory Sinus, Arch. f. Augenh., lxvii, 101. 
**Van der Hoeve, J. Enlargement of Blind Spot, an Early Symptom of 
Optic Nerve Affection Due to Posterior Nasal Accessory Sinus (Bibl.), Arch. 
of Ophth., xl, 30; Arch. f. Augenh., lxx, 155. 

Gradel, H. S. The Blind Spot, Illinois Med. Jour., January, xxviii, 170. 

Peter, L. C. Perimetric Studies of the Normal and Pathologic Blind 
Spot of Mariotte, Tr. Am. Acad, of Ophth. and Oto-Laryn., October, 1915. 



BIBLIOGRAPHY 215 

Szilv, Von. Ring Scotoma Extending from Blind Spot in Cerebral Choked 
Disc, Klin. Monatsbl. f. Augenh., February, 1913, p. 196. 

Fridenberg, P. Central Scotoma and Blind Spot Associated, Ophthal- 
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Aubert. Graefe-Saemisch, 1st ed., ix. 

Bardsley. Ophthalmoscope, vi. 

Birch-Hirschfeld. Graefe's Archiv, lxv. 

Bjerrum. Nordisk Ophthal. Tidskrift, p. 113. 

Fuchs. Graefe's Archiv, xxxi. 

Fuchs. Text-book of Ophthal., 1908. 

Mendel. Centralbl. f. Augenh., 1901. 

de Lapersonne. Arch, de Ophthal., 1902. 

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Smith, Priestley. Trans. Ophth. Soc. U. K., 1906. 

Snellen. Trans. Int. Med. Cong. Budapest, 1909. 

Masso. Klin. Monatsbl. f. Augenh., 1910. 

Haycroft. Jour. Physiol., August, 1910. 

Harlan. Trans. Amer. Ophthal. Soc, 1900. 

Cohen. Amer. Acad, of Ophthal. and Otolaryng., 1912. 

Epeleers. Klin. Monatsbl. f. Augenh., November, 1912. 

Rubel. Klin. Monatsbl. f. Augenh., 1912. 

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Markbreiter. Ztschr. f. Augenh., May, 1914. 

Onodi. Ztschr. f. Augenh., May, 1914. 

Peter, L. C. Ophthalmic Record, July, 1915. 

Donders. Onderzock Physiolog. Lab., Utrecht, 1852, vi. 

Mariotte. Philosophical Trans., 1670, ii, 59. 

Leber. Graefe-Saemish, 1st ed., vii. 

Wilbrand and Saenger. Neurologie des Auges. Vossius, Graefe's Archiv , 
xxix. 

Samuelsohn. Graefe's Archiv, 1882, xxviii. 

CHIASM. 

Gehrung, J. A. Disease of the Optic Chiasm, New York Eye and Ear 
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de Schweinitz, George E., and Carpenter, J. T. Ocular Symptoms of 
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**Redslob, E. Bitemporal Hemianopsia Diabetes Insipidus (Bibl.), Klin. 
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Pankstat. Bitemporal Hemianopsia, Klin. Monatsbl. f. Augenh., May, 
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Schnabel. Temporal Hemianopsia, Ztschr. f. Augenh., July, 1905. 

Veasey, C. A. Bitemporal Hemianopsia, Am. Jour. Med. Sci., February, 
1905. 
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de Lapersonne, F. Acromegaly and Bitemporal Hemianopsia, Arch. 
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Kerry, R. Case of Acromegaly, Ophth. Rec, July, 1906. 



216 BIBLIOGRAPHY 

Golezovoski, J. Bitemporal Double Hemianopsia, Ann. d'Ocul., Novem- 
ber, 1906, p. 396. Lesion of Chiasm and Basal Meningitis, Rec. d'Ophth., 
June, 1906, p. 361. 

Hansell, H. F. Ocular Symptoms and Tumor of the Pituitary Body, 
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• **Bortels, M. Epithelial Tumors of the Region of the Hypophysis (Bibl.), 
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Peck, W. H. Cystic Degeneration of the Pituitary Body, with Pressure 
on the Chiasm, Ophthalmology, April, 1906. 

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Uhthoff, W. Anomalies of Development with Temporal Hemianopsia 
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Dhloer. Cysticercus Involving Chiasm and Optic Nerve, Klin. Monatsbl. 
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Levitsky. Bitemporal Hemianopsia and Sphenoidal Disease, Klin. 
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Uhthoff. Eye Symptoms in Affections of Hypophysis and in Acromegaly, 
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Gordon, A. Bitemporal Hemianopsia followed by Optic Atrophy of 
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Kollner. Tumors of the Hypophysis, Centralbl. f. p. Augenh., July, 1910, 
p. 211. 

Sherer, J. W. Horizontal Heteronymous Hemianopsia, Ann. Ophth., 
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Poffereberger, A. T., Jr. Binocular Vision and the Optic Chiasm, 
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Heinrischdorff. Psammoma in Anterior Angle of Chiasm, Klin. 
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Walker, C. B. Study of Bitemporal Hemianopsia with New Instruments 
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Cushing. Disease of the Hypophysis, p. 319; Perimetric Deviations with 
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Large, O. Disease of Hypophysis and Neighboring Parts and Binasal 
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Doyne, R. W. Acromegaly; Pituitary Tumors; Showing Fatigue of 
Fields for Colors before Failing of White Field, Proc Roy. Soc. Med., May, 
1913. 

SINUS DISEASE. 

Fish, H. M. Frontal Sinusitis and Partial Ophthalmoplegia Interna, New 
York Med. Jour., February 27, 1904. 

Posey, W. C. Ocular Symptoms of Affections of Accessory Sinuses of the 
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Posey, W. C. Ophthalmic Phases of Nasal Accessory Sinus Disease, Jour. 
Eye, Ear, and Throat Dis., March-April, 1905. 



BIBLIOGRAPHY 217 

Clegg and Hay. Disease of Posterior Ethmoidal Cells with Ocular Symp- 
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de Kleihn, A. Optic Nerve Disease with Disease of Posterior Accessory 
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**Evons, J. J. Field of Vision in Disease of Orbit and Nasal Sinuses (Bibl.), 
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**Ruhel, E. Enlargement of Blind Spot and Central Scotoma in Sinus 
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de Schweinitz, George E. Homonymous Crescentic Scotomas in Eth- 
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DISEASE OF THE CHOROID, RETINA AND OPTIC NERVE. 

Buller. Toxic Amblyopia Caused by Wood Alcohol, Montreal Med. 
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Wood, Carey A., and Buller. Poisoning by Wood Alcohol, Jour. Am. 
Med, Assn., 1904, pp. 72, 1058, 1117, 1213, 1289. 

**Birch-Hirschfeld, A. Pathogenesis of Toxic Amblyopia (Bibl.), 
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Hallmann. Changes in the Visual Field after Alcohol Debauch, Mitt. 
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O'Kinealy, F. An Anomalous Case of Toxic Amblyopia, Tr. Ophth. Soc. 
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Harman, N. B. Visual Fields in Tobacco Amblyopia, Lancet, 1904, 
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Sesuelinsky. Changes in the Visual Field after Intoxication with Nitro- 
benzol and Nitrous Oxid Gas, Mitt, aus der Augenklin. in Jerjeu, 1904, ii. 

Bulson, A. E., Jr. Toxic Amblyopias, with Reference to Those Produced 
by Tobacco and Coffee, Ann. Ophth., 1904, p. 907. 

Reber. Toxic Amblyopia of Diabetic Origin, Ophth. Rec, xix, 121. 

Masso. Quinine Amaurosis, Klin. Monatsbl. f. Augenh., April, 1910, p. 519. 
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**R6nne. Pathologic Anatomy of Diabetic Toxic Amblyopia (Bibl.), 
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Bar. Tobacco Amblyopia (Dis.), Klin. Monatsbl. f. Augenh., October, 
1905. 



218 BIBLIOGRAPHY 

Schnable, G. Influence of Caffein on Field of Vision in Quinine Ambly- 
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Bulson, A. E., Jr. Coffee Amblyopia, Am. Jour. Ophth., February, 1905. 

Fergus, A. F. Sympathetic Degeneration, Brit. Med. Jour., December 
29, 1906. 

Bar, K. An Investigation of Tobacco-Alcohol Amblyopia, Arch. f. 
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Seeligsohn, W. Quinine Amaurosis, Centralbl. f. p. Augenh., June, 1906, 
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Galzonavoski, J. Toxic Amblyopia Caused by Copper, Ophth. Rec, 
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v. Krudener, H. Blinding by Atoxyl, Methyl Alcohol, Bisulphate of 
Carbon and Male Fern, Ztschr. f. Augenh., 1906. 

Holz, F. C. Antipyrin Amaurosis, Arch. Ophth., March-May, 1906. 

Lindenmeyer. Retrobulbar Neuritis with Burn of Skin, Klin. Monatsbl. 
f. Augenh, June, 1906. 

Sinni and Fortin. Central Scotoma in Congenital Amblyopia, Arch, 
d'Ophth., November, 1906. 

Hawthorne, C. O. Retinal Embolism; Two Cases Retaining Normal 
Standard of Central Visual Acuity, Practitioner, June, 1907, p. 813. 

Krauss, F. Embolism of Cilioretinal Artery, Ophth. Rec, April, 1907. 

Kliffie and Weil, P. Parkinson's Disease with Optic Atrophy and Gum- 
ming of Lids, Ann. d'Ocul., July, 1908, p. 61. 

Landolt, M. Scotoma due to Opaque Nerve Fibers, Arch. d'Ophth., 1909, 
p. 550. 

**Stogart, K. Family Progressive Degeneration of Macular Region (Bibl.), 
Graefe's Arch. f. Ophth., lxix, 525. 

Yamaguchi, H. Central Scotoma in Beri-beri, Klin. Monatsbl. f. Augenh., 
May, 1909, p. 517. 

Ronne, H. Does Optic Atrophy of Tabes Attack the Ganglion Cells or 
Nerve Fibers? Graefe's Arch. f. Ophth., lxxii, 481. 

Raymond and Koenig, E. Hereditary Atrophy of Optic Papilla, Rec. 
d'Ophth., 1909, p. 65. 

Masso. Bjerrum's Field in Neuritis of Papillomacular Bundle and Sym- 
pathetic Ophthalmia, Klin. Monatsbl. f. Augenh., April, 1910, p. 519. 
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Feilchenfeld, W. Sun-Blindness, Deutsch. med. Wchnschr., February 10, 
1910, No. 6; Jour. Am. Med. Assn., March 19, 1910, p. 1014. 

Peter, L. C. Ophthalmic Studies in Chronic Interstitial Nephritis, New 
York Med. Jour., August 20, 1910. 

Laubee. So-called Retinitis Prenatalis Albescens, Klin. Monatsbl. f. 
Augenh., February, 1910, p. 133. 

Komoto, J. Retino-Choroiditis Juxtapapillaris, Nippon Gank. Gakukwai 
Zasshi, June, 1910. 

Kollner, H. Color Disturbance in Detachment of the Retina, Ztschr. f. 
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**Babinski. Visual Field and Central Vision in Tabetic Optic Atrophy 
(Bibl.), Soc. d'Ophth. de Paris, February, 1907. 

Parsons. Night Blindness, Lancet, February 22, 1908, p. 555. 
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BIBLIOGRAPHY 219 

Bardsley, J., Jr. A Family of Hemeralopes, Johns Hopkins Hosp. Bull., 
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Hancock, W. I. Field and Fundus Changes in Obstruction of Central 
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Edmund-Jenson. Retinochorioditis, Adjoining Optic Disc, Graefe's Arch 
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Wernicke, O. Ring Atrophy of Choroid and Retina, Arch. f. Augenh. 
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of Pathologic Excavation, Klin. Monatsbl. f. Augenh., January, 1910, p. 50 
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Ronne. Visual Fields in Hereditary Optic Atrophy, Ibid., March, p. 331 
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Nakamura. Hereditary Optic Atrophy, Klin. Monatsbl. f. Augenh. 
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Uhthoff, W. Visual Disturbance with Tower Skull, Tr. XXXVI Ophth 
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**R6nne, H. Hemianopic Central Scotoma in Disseminated Sclerosis and 
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Fuchs, E. Field of Vision in Tabetic Optic Atrophy, Ann. Ophth. Soc. : 
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Cushing and Walker. Distortion of Visual Field with Brain Tumor 
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Lagrange, F. Uremic Amaurosis in Pregnant Women, Arch. d'Ophth. 
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**R6nne. Nerve Fiber Defects in Visual Field, Especially Nasal Field 
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H6eg, N. Opaque Nerve Fibers, Klin. Monatsbl. f. Augenh., November, 
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Price and Heed. Binasal Hemianopsia in Tabetic Optic Atrophy, Sec. 
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Cushing, H. Perimetric Deviations with Pituitary Lesions, Med. Rec, 
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Claiborne, J. H. Permanent Ring Scotoma, Arch. Ophth., xliii, 516. 

Claiborne, J. H. Sudden Bilateral Blindness Following Anger, with 
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Kollner. Functional Papilledema of Nasal Half of Retina in the 
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Eppenstein. Perimetry in Paracentral Scotoma, Ztschr. f. Augenh., xxxii, 
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220 BIBLIOGRAPHY 

Igersheimer, J. Scotoma and the Significance of Lumbar Puncture in 
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Kobajashi. Recurrent Central Scotoma, Nippon Gank. Zasshi., July, 1914. 

Marx. Ring Scotoma in Ocular Syphilis, Klin. Monatsbl. f. Augenh., liii, 
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Frenkel, E. Boundaries of Visual Field in Choked Disc, Konigsberg 
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de Schweinitz, George E. Homonymous Crescentic Scotomas in Eth- 
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Rogalla, B. Disease of Optic Nerve with Defect of Visual Field, Berlin 
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Posey, W. C. Unusual Changes in Visual Fields, Jour. Am. Med. Assn., 
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Grassmann. Wound by Hay Fork; Central and Ring Scotomas, Klin. 
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Liebrecht. Visual Field in Shot Wounds, Deutsch. med. Wchnschr., 
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**Hepburn, M. L. Visual Fields in Retinitis Pigmentosa (Bibl.), Royal 
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Stolling. Ring Scotoma in Retinitis Pigmentosa, Klin. Monatsbl. f. 
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**Kollner, H. Visual Fields in Typical Pigmentary Degeneration of 
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Sopemaker, Wm. T. Retinitis Pigmentosa. 

Calhoun, F. P. Optic Atrophy Caused by Uterine Hemorrhage, Ophth. 
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Kampherstein. Pathology and Pathogenesis of Choked Disc, Klin. 
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Uhthoff, W. Eye Symptoms of Disseminated Sclerosis, Ophthalmoscope, 
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Von Szily. Visual Field in Papillitis and Optic Neuritis, Klin. Monatsbl. 
f. Augenh., January, 1913, p. 90. 

Peter, L. C. Altitudinal Hemianopsia, Unilateral and Bilateral, Phila- 
delphia Pol. Ophth. Soc, December 12, 1912; Ophth. Rec, xxii, 106; 
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Hegner. Defects of Visual Fields, Klin. Monatsbl. f. Augenh., January, 
1913, p. 108. 

Fridenberg, P. Central Scotoma and Blind Spot Associated, Ophthal- 
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Gashiguard, P. Persistence of Light Sensations in Blind Field in Hemi- 
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Claiborne, J. H. Ring Scotoma from Chorioretinitis Syphilitica, Virginia 
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Komoto. Annular Chorioretinal Atrophy, Nippon Gank. Zasshi., June, 1913. 

Kooy, J. M., and de Kleijn, A. Diseases of Optic Nerve and Scotomas 
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BIBLIOGRAPHY 221 

Shorten, J. M. Retro-ocular Neuritis Caused by Sun Traumatism, 
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Auberet. Scotoma from Watching Solar Eclipse, Arch. d'Ophth., Febru- 
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Lohman, W. Red-green Blindness with Snow Blindness and Experimental 
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Speleirs Ring Scotoma with Sun Blinding, Klin. Monatsbl. f. Augenh., 
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Stache. Eclipse Scotoma, Klin. Monatsbl. f. Augenh., November, 1916, 
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Werdenberg. Solar Retinitis and Eclipses, Ztschr. f. Augenh., xxx, 273. 
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Kaszietski. Twelve Cases of Eclipse Scotoma, Postep. Oked., 1912, Nos. 
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BRAIN AND CORTEX. 

Beevor, C. E., and Collier, J. Cortical Localization of Vision: A Case 
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Hirschelwood, J. Ward. Blindness with Right Homonymous Hemian- 
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Gamble, W. E. Visual Disturbance in Brain Injury, Jour. Am. Med. 
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Goldzieher, N. Brain Injury and Blindness, Centralbl. f. Prakt. Augenh., 
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Ereslin, E. Homonymous Hemianopsia from Carbon Monoxide Poison, 
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Von Duyse. Incomplete Bilateral Hemianopsia from Gunshot Wound, 
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**Carlini. Blindness Following Hemorrhage (Bibl.), La Clinica Oculistica, 
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222 BIBLIOGRAPHY 

Hawthorne, C. O. Homonymous Hemianopsia from Metastasis, Lancet, 
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Wilbrand, H. Macular Hemianopic Disturbance of Reading and von 
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Bardsley, J., and Cushing, H. Alteration in Color Fields in Brain Tumor, 
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**Lenz, G. Path of Cerebral Visual Tract and Its Bearing on Anatomy and 
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Best, F. Localizing Diagnosis of Hemianopsia, Munch, med. Wchnschr., 
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Doyne, R. W. Visual Sensation, Perception, Appreciation and Judgment, 
Ophthalmoscope, 1910, viii, 474. 

Endelmann, L. Homonymous Hemianopsia with Alexia and Agraphia, 
Arch. f. Augenh., lxxi, 177. 

Ingegnieros, J. Pseudodyschromatopsia in Verbal Amnesia in Cortical 
Hemianopsia, Ophthalmology, viii, 290. 

Henschen, S. E. Circumscribed Nutritional Areas in Occipital Lobe and 
Their Relation to Visual Centers, Graefe's Arch. f. Ophth., Ixviii, 195; Ophthal- 
moscope, x, 477. 

**Lenz, G. Localizing Significance of Preservation of Central Vision in 
the Hemianopic Field (Bibl.), Klin. Monatsbl. f. Augenh., liii, 30. 

Morbrun, A. A. Quandrant Hemianopsia, Paris Thesis, Klin. Monatsbl. 
f. Augenh., liii, p. 283. 

Bonnet, P. Central Visual Centers, Algiers Thesis, 1912. 
' Uthoff, W. Congenital Blindness from Defect of Occipital Lobe, Klin. 
Monatsbl. f. Augenh., March, 1913, p. 367. 

Casamojor, L. Fields in Tumor of Right Temporal Lobe, Med, Rec, 
lxxxiii, 866. 

Thoden von Velzen, S. K. Visual Center, Deut. Zeit. f. Nervenh., xlv 
434. 

Lancaster, W. B. So-called Binasal Hemianopsia in Brain Tumor, Boston 
Med. and Surg. Jour., clxviii. 

Vail, D. T. Cerebral Localization from Standpoint of the Oculist, Jour. 
Ophth. and Oto-Laryngol. vii, 239. 

Arbolida, A. Homonymous Hemianopsia after Typhoid Fever, Anales 
de Optal., xvi, 303. 

La Monaco, D., and Sammartino, U. Blinding from Excision of Occipital 
Lobes and Ophthalmus, Arch, di Farmacol. Sper. Roma, xvii, 13. 

Cross, F. R. Homonymous Hemianopsia without Other Evidence of 
Organic Disease, Ophth. Soc. U. K., xxxiv, 200. 



BIBLIOGRAPHY 223 

Hawthorne, C. O. Cases in Which Homonymous Hemianopsia is the 
Principal or Only Evidence of Organ. Disease, Ophth. Soc. U. K., xxxiv, 195. 

Minkovoski. Visual Cortex and Its Relation to Primary Optic Centers, 
Corresp.-Bl. f. Schweiz. Aerzte., lxiv, 1010. 

Ballen, F. E., and Mayou, S. Cerebral Degeneration Associated with 
Macular Changes, Roy. Soc. Med. Ophth. Sci., February 3, 1915; Ophth. 
Rec, xxxiv, 91. 

Funkhouser, E. B. Visual Cortex Localization, Structure, and Function, 
Jour. Exp. Med., xxi, No. 6. 

Suker, G. F. Lesion in Upper Portion of Cuneus, Clin. Ophth. Soc, March 
15, 1915; Jour. Ophth. and Oto-Laryngol., 1915, ix, 152. 

Brommell, B., and Bolton, J. S. Bilateral Lesion in Occipital Lobes: 
Position of Cortical Area for Macular as Distinct from Non-macular or 
Panoramic Vision, Edin. Med. Jour., 1915, xv. 

Cushing and Walker. Distortion of Visual Fields in Brain Tumor, 
Brain, xxxvii, 341. 

Pick. Localization in Visual Tracts with Disturbance of Orientation, 
Prager. med. Wchnschr., 1915, No. 8; Klin. Monatsbl. f. Augenh., liv, 543. 

Ronne. Incongruity and Asymmetry in Homonymous Hemianopic Visual 
Fields, Klin. Monatsbl. f. Augenh., liv, 399. 

Posey and Farr. Left Homonymous Hemianopsia' in Workers in Lead, 
Univ. Pa. Med. Bull., March, 1910. 

Bromwell, B. Intracranial Tumor with Alterations in Color Fields. 
**Ronne. Significance of Macular Preservation of Vision: The Hemionopic 
Field (Bibl.), Klin. Monatsbl. f. Augenh., September, 1911, p. 289; Ophthal- 
mology, x, 347. 

Lohman. Disturbances of the Visual Functions. 

FUNCTIONAL NERVOUS DISEASES. 

Wolffberg, L. Perimetry, with Special Reference to Traumatic Neurosis, 
Arch. Ophth., November, 1904. 

Mahillou. Value of the Color Fields in Certain Traumatic Neuroses 
Rec. d'Ophth., January, 1904. 

Pick, A. Diagnostic Significance of Hemianopic Hallucinations: Scintil- 
lating Scotoma, Am. Jour. Med. Sci., January, 1904. 

Fish, H. M. Hysterical Asthenopia and Sinus Disease, Ophthalmology, 
October, 1904. 

Kipp, C. J. Scintillating Scotoma, Jour. Am. Med. Assn., April 22, 1905. 

Bortels. Hysteria and Neurasthenia in Ophthalmology, Ztschr. f. 
Augenh., November-December, 1907. 

Sulzer. Transient Amaurosis with Preservation of Fixation Point (Dis.), 
Societe d'Ophth. de Paris, March, 1907. 

Kafka, V. Hemianopic Contractions of Visual Field, Prager. med. 
Wchnschr., No. 33. 

Misno. Visual Field in Japanese, Nippon Gank. Zasshi, January, 1908. 

Gowers, W. R. Prodrones of Migraine, Brit. Med. Jour., January 12, 
1909. 

de Schweinitz, G. E. Relation of Visual Field to Investigation of Certain 
Psychoses and Neuroses Univ. Pa. Med. Bull., January 30, 1910. 



224 BIBLIOGRAPHY 

Gonzales, J. de J. Investigation of Visual Fields in Hysteria, Klin. 
Monatsbl. f. Augenh., April, 1910, p. 519. 

Pichler, A. Causes and Treatment of Temporary Partial Amaurosis, 
Wien. klin. Wchnschr., January 12, 1911; Am. Jour. Ophth., xxviii, 133. 

Zentmayer, W. Migraine with Ring Scotoma, Ann. Ophth., xxi, 279. 

Ronne, H. Hysteric Defects of Visual Fields, Klin. Monatsbl. Augenh., 
Hi, 372; Ophthalmology, vii, 222. 

Osmond, A. W. Permanent Hemianopsia Following Severe Migraine, 
Ophth. Rev., xxxii, 193. 

Filehue. Origin of Flicker Scotoma, Deutsch. Arch. f. klin. Med., cxii, 
190. 

Eldridge-Green, F. W. The Scotoma of Migraine, Lancet, April 24, 
1915, p. 847; May 8, p. 992. 

Higgins, C. The Scotoma of Migraine, Lancet, May 1, 1915, p. 935. 



INDEX. 



Accommodation, 77 
Albuminuric retinitis, 111 
Altitudinal hemianopsia in brain 
tumor back of chiasm, 173 ; 
in disease of chiasm, 168, 173 
Amblyopia, 188 

central, in disease of chiasm, 176 
of calcarine fissure, 188 
crossed, in disease of optic radia- 
tions, 180 
sympathetic, of Fergus, 155 
toxic, 151 
Anatomic relations of optic nerve, 69 
Anatomy of optic nerve, 68 

of visual tracts, 66 
Angular defects in field, 96 
gyrus, 75 

concept centers in, 188 
psychic centers in, 75, 188 
Anopsias, 89 

color, 93, 184 

in disease of optic radiations, 
183, 184 
hemi-, 90 

altitudinal, 90 
binasal, 90 
bitemporal, 90 
heteronymous, 90 
homonymous, 90 
line of demarcation, 90 
quadrant, 90 

symptoms associated with, 
189 
Anterior corpora quadrigemina, 179 
fields in disease of, 179 
Appendix, 207 

Arrangement of optic nerve fibers, 67 

Atrophy of optic nerve in cerebellar 

hereditary ataxia, 159 

in chronic myelitis, 158 

consecutive, 162 

in disease of chiasm, 176 

of primary optic 

centers, 177 
of tracts, 177 
following bulbar par- 
alysis, 158 
choroiditis, 165 
retinitis, 165 
15 



Atrophy of optic nerve in Friedreich's 
ataxia, 159 
primary, 156 
secondary, 162 
in spastic paraplegia, 

158 
in syringomyelia, 158 
in tabes dorsalis, 156 
in tower skull, 159 

Autoperimetry, 32 



B 



Bibliography, 210 
Binasal hemianopsia in choked disc, 
136 
interpretation of, 
136 
in disease of chiasm, 169 
in tabes, 157 
Binocular fields, 30 
Bitemporal hemianopsia in disease of 

chiasm, 169 
Bierrum's method of examining fields, 
43, 44 
symptom in glaucoma, 143 
Blackboard perimeter. See Campim- 

eter. 
Blind spot, distance from fixation 
center, 29 
enlargement of, 85 

in choked disc, 134 

in diabetes, 114 

evidence of, 86 

in nephritis, 112 

in optic neuritis, 146 

in papilledema, 134 

in papillitis, 134 

in sinus disease, 148, 149, 

150 
in solar and electric 

retinitis, 116 
in toxic amblyopia, 153 
of Mariotte, 29 
measuring of, 44 
normal variations of, 86 
shape of, 29 
size of, 29 
study of, on campimeter, 44 



226 



INDEX 



Blindness, psychic, 81 
Blood supply of retina, 68 

influence of, in disease, 
68 
Blue-blindness in detachment of 

retina, 122 
Bulbar paralysis, fields in, 158 



Calcarine fissure, 188 

macular centers in, 75, 188 
visual centers in, 75, 188 
Campimeter, 35 

advantages of, 48 
construction of, 37 
disadvantages of, 48 
Duane's, 52 

examination of blind spot on, 44 
of color fields on, 42 
of scotoma on, 43 
measuring of light projection on, 

43 
Peter's hand, 49 

advantages of, 51 
use of, 51 
practical use of, 40 
Centers, visual, concept, 188 
cortical, 184 
lower, 177 
psychic, 188 
Central amblyopia, in disease of cal- 
carine cortex, 176 
of chiasm, 176 
of internal capsule, 180 
of optic radiations, 180 
of primary optic centers, 
180 
artery, embolism of, 162 

thrombosis of, 162 
vision, 17 

method of obtaining, 18 
Cerebellar hereditary ataxia, 159 
Charts, campimetric, 64 

for recording fields, 22, 35, 36, 63 
Chiasm, 71 

anatomic environment of, 71 
disease of, 165 

color fields in, 176 

early perimetric symptoms 

of, 176 
field changes in, 1.68, 177 
irregular fields in, 176 
Choked disc, 134 

binasal quadrant defects in, 

136, 137 
enlargement of blind spot in, 

134 
field changes in, 134, 135, 

136, 137 
reversal of color fields in, 136 
scotomata in, 135 
Choriocapillaris, 67 



Choroiditis, 104 

color changes in, 103, 104 
field changes in, 104 
scotomata in, 104 
negative, 104 
positive, 104 
ring, 104 
Chronic myelitis, fields in, 158 
Cilioretinal vessel, 128 
Coloboma of choroid and retina, 130 
of macula, 132 
of optic nerve, 131 
Color amnesia, 184 

blindness, taking of fields in, 43 
changes in chroiditis, 102 
in fields, 97, 98 
in retinitis, 103 
fields, in disease of optic radiation, 
183 
examination of, 42 
size of, 27 
sensibility in periphery of field, 
29 
Commotio retinae, fields in, 124 
Concentric contraction of field, 94 

plus unequal defects, 95 
in glaucoma, 139 
in hysteria, 193 
in primary optic atrophy, 
156 
Concept centers, 81 
Consecutive atrophy, 162 

fields in, 163 
Corpora quadrigemina, 72 
Corresponding retinal halves and 
quadrants, 21 
points, 20 
Cortical visual centers, 73, 80, 184 
Crossed amblyopia, 180 

in chiasmal disease, 180 
in disease of cortex, 180, 188 
of optic radiations, 180 

188 
of primary optic centers, 
180 
Cuneus, 75 

calcarine fissure in, 75 
higher visual centers in, 75 



D 



Definition of perimetry, 17 

de Schweinitz's measurements of 

normal color fields, 29 
Detachment of retina, 121 

field changes in, 122 
scotoma in, 122 
Disease of chiasm, 165 

altitudinal hemianopsia in, 

173 
binasal hemianopsia in, 172 
bitemporal hemianopsia in, 
172 



INDEX 



227 



Disease of chiasm, causes of, 169 
central amblyopia, 176 
color changes in, 176 
complicated by hysteria, 176 
field changes in, 165 
irregular forms of hemianop- 
sia in, 175 
localizing symptoms in, 165 
types of hemianopsia, 172 
of choroid, 103 

field changes in, 104 
optic atrophy following, 165 
positive scotoma in, 104 
of cortical visual centers, 185 
of cuneiform bodies, 187 
of external geniculate bodies, 179 
of optic radiations, 182 
atrophy in, 182 
color amnesia in, 184 

anopsia in, 183 
crossed amblyopia in, 

180 
dyschromatopsia in, 184 
field changes in, 183 
homonymous hemianop- 
sia in, 182 
incomplete anopsias in, 
184 
of papilla, 134 
of primary optic centers, 177 

crossed amblyopia 
in, 180 
of retina, 107 

field changes in, 108 
scotoma in, 108 
of tracts, 177 
Double innervation of macula, 176 
Duane's charts, 53 

tangent curtain, 53 
Dyschromatopsia, 184 



Edixger's dictum, 152 
External geniculate body, fields in dis- 
ease of, 179 
Effect of activity of the retina on 
normal field, 23 
of drugs on the normal field, 25 
of fatigue on the normal field, 25 
of forward attachment of retina 

on normal field, 24 
of intelligence of patient on 

normal field, 24 
of light on normal color field, 25 

on normal form field, 25 
of refractive errors on normal 

field, 24 
of shape of the orbit on normal 

field, 23 
of size of the pupil on normal 

field, 24 
of width of palpebral fissure, 24 



Embolism of central arterv, 116, 127, 

161, 201, 204 
Entoptic study, 19, 32 

limitations of, 19 

in migraine, 201 

Examination of color fields^ 42, 43 

of fields on campimeter, 40, 41 
for scotomata, 43 



Fatigue field, 100, 101, 197 

of Forster, 198, 199 

methods of taking, 197, 198 
199 

in neurasthenia, 43, 197 

of Scheele, 199 

of von Reuss, 101, 197 

of Wilbrand, 197 
Fields in accessory sinus disease, 147 
binocular, 30 
in bulbar paralysis, 158 
in choked disc, 134 
in choroiditis, 104 
in chronic myelitis, 158 
in coloboma of choroid and retina, 
130 

of macula, 132 

of optic nerve, 131 
color, changes in, 97 
in commotio retinae, 124 
in consecutive atrophy, 163 
in detachment of retina, 121 
in disease of anterior corpora 
quadrigemina, 179 

of chiasm, 168 

of external geniculate body, 
179 

of optic radiations, 182 

of pituitary body, 168 

of primary optic centers, 177 

of pulvinar, 179 

of thalamus, 179 

of tracts, 177 
in embolism of central artery, 127, 

161 
examination of, 42 
fatigue, 100, 101, 197, 198, 199 
in Friedreich's ataxia, 159 
in functional nervous diseases, 

190 
in glaucoma, 138 

acute, 138 

chronic, 139 
in hereditary cerebellar ataxia, 159 
in hysteria, 191, 194 
in insular sclerosis, 157 
in interstitial neuritis, 145 
in intra-ocular disease, 102 
in Leber's disease, 160 
method of studying on campim- 
eter, 40, 41 
in migraine, 201 



228 



INDEX 



Fields in neurasthenia, 196 
normal, 22 

color, 27, 28, 29 
factors which influence, 22, 
23, 24, 25, 26 
bones of orbit, 

23 
drugs, 25 
fatigue, 25 
forward attach- 
ment of re- 
tina, 24 
intelligence of 

patient, 24 
light, 25 
palpebral fis- 
sure, 24 
refraction, 242 
retinal activity, 

. 23 
size of pupil, 24 
in opaque nerve fibers, 132 
in optic neuritis, 145 
in overshot fields, 92 

significance of, 92 
in papilledema, 134 
in papillitis, 134 
in paralysis agitans, 158 
in paresis, 157 
in perineuritis, 145 
in postneuritic atrophy, 163 
in primary optic atrophy, 156 
in reentering angular defects, 96 
in remote hemorrhages, 130 
in retinitis, 107 
diabetic, 114 

of Hodgkin's disease, 115 
leukemic, 114 
nephritic, 111 
of pernicious anemia, 114 
pigmentosa, 118 
solar and electric, 115 
syphilitic, 110 
in retrobular neuritis, 150 
in rupture of choroid and retina, 

126 
in secondary atrophy, 162 
size and shape of, 22, 26 
in spastic paraplegia, 158 
in syringomyelia, 158 
in thrombosis of central artery, 
127, 162 
of retinal veins, 129 
in toxic amblyopia, 151 
in traumatic anesthesia of retina, 
126 
hole in macula, 126 
Forster's method of taking fatigue 

field, 198 
Fortification spectrum in migraine, 201 
Friedreich's ataxia, fields in, 159 
Fuch's coloboma, 131 
Functional nervous diseases, 190 
classification of, 190 



Geniculate body, external, 72 
disease of, 179 
fields in, 179 
General pathology of fields, 82 
Glaucoma, 138 

Bjerrum's symptom in, 143 
central field defects in, 142, 143 
clinical types of, 138 

acute, 138, 139 
chronic, 139, 140 
color defects in, 141, 144 
concentric contraction in, 141 
early contraction of nasal field, 

139 
field changes in, 138-144 
optic atrophy in, 144 
scotoma in, 142, 143 
sector defects in, 142, 143 
Green vision in retinal detachment, 
122 



H 



Haitz's stereoscopic cards, 46, 64 
Hand method of taking fields, 23 

campimeter, 49 
Hemianopsia, 90 
altitudinal, 90 
associated with choked disc, 94, 

137 
binasal, 90 

in chiasmal disease, 172 
bitemporal, 90 

in chiasmal disease, 172 
in chiasmal disease, 173 
color, 93 
in disease of chiasm, 168 

of primary optic centers, 177 
dividing line in, 90 
heteronymous, 90 
homonymous, 90 
hysteria and, 94, 193 
incomplete, 93 

color, 93 
overshot fields in, 92 

significance of, 92 
in pituitary disease, 168 
in tract disease, 177 
Hereditary cerebellar ataxia, 159 
Hess's method of outlining central 

scotoma, 46 
Hippocampus minor, 75 
Hirschberg's measurements of normal 

color fields, 28 
Hysteria, 191 

amaurosis in, 193 
anesthesia of retina in, 193 
color amblyopia in, 196 
concentric contraction in, 193 
dyschromatopsia in, 195, 196 
interlacing of colors in, 195 
ocular symptoms of, 191 



INDEX 



229 



Hysteria, red-blue reversal in, 195 
red-green reversal in, 195 
reversal of color fields in, 195 
tubular fields in, 194 
types of field changes in, 192 



Idiopathic hemeralopia, 107 
field changes in, 107 
nyctalopia, 106 

color changes in, 107 
fields in, 106, 107 
Indirect vision, 17 
Insular sclerosis, 157 

field changes in, 157 
Interlacing of color fields, 98, 99 
in brain tumor, 136 
in hysteria, 195 
Interstitial optic neuritis, 145 

enlargement of blind 

spot in, 146 
field changes in, 146 
Intra-ocular disease, 102 

behavior of colors in, 103 
character of scotomata in, 
103 
Inversion of color fields, 98 

in brain tumor, 136 
hysteria, 195 



Law of corresponding retinal points, 
20 
of direction, 19 
of projection, 19 
Leber's disease, 159 

central scotoma in, 159 
fields in, 159 
light, day, need of, in perimetry, 25 
effect of, on color fields, 25 

on form fields, 25 
projection, measuring of, on 
campimeter, 49 
locomotor ataxia, atrophy in, 156 
field changes in, 156, 157 
hemianopsia binasal, in, 157 



M 



Macula, 17 

coloboma of, 132 
double innervation of , 172, 176 
involvment of, in chiasmal dis- 
ease, 172, 180 
in disease of cortex, 180 

of optic radiations, 180 
Mariotte's blind spot, 29. See Blind 

spot. 
^Method of charting fields, 61, 63 



Method of constructing a campimeter, 
of examining fields, 32 
Bjerrum's, 44 
on campimeter, 40 
advantages of, 49 
limitations of, 34 
by hand, 33 

advantages of, 34 
limitations of, 34 
in illiterate patients, 34 
on perimeter, 56 
in scotoma, 43 

central, 46 
semiconscious patients, 
34 
of studying indirect vision, 19 
Migraine, 200 

color display in, 200 
field changes in, 201 
fortification spectrum in, 201 
scintillating scotoma in, 201 
scotoma in, 201 
Mind-blindness, 81, 189 

associated with hemianopsia, 
189 
Monocular fixation, field changes in, 

157 
Multiple sclerosis, field changes in, 157 

scotomata in, 157 
Myopia, detachment of retina in, 122 



X 



Negative scotoma, 84 

in choroidal disease, 48 

in choroiditis, 104 

in commotio retinae, 124 

in glaucoma, 141 

in insular sclerosis, 157 

in Leber's disease, 160 

in primarv optic atrophy, 156 

in retinitis, 107, 108, 110, 

111, 114, 115 
in sinus disease, 148 
in toxic amblyopia, 152 
Neurasthenia, 196 
fatigue in, 196 
field changes in, 197 
Forster's field in, 198, 199 
oscillating field, 199 
von Ruess's field in, 101, 197 
Wilbrand's field in, 197 
Neurons of retina, 67 
inner, 68, 79 

blood supply of, 68 
outer, 67, 79 

blood supply of, 67 
Normal color field, 27, 28, 29 

effect of light on, 26 
size of, 27 
form field, 26 

effect of activity of 
retina on, 23 



230 



INDEX 



Normal form field, effect of drugs on, 25 
of fatigue on, 25 
of forward attach- 
ment of retina on, 
24 
of intelligence of 

patient on, 24 
of light on, 25 
of refractive errors 

on, 24 
shape of orbit on, 

23 
of size of pupil on, 

24 
of width or palpe- 
bral fissure on, 24 



Ophthalmic migraine, 200 

fields changes in, 202 
hemianopsia in, 204 
resemblance to epilepsy, 200 
types of, 200 
Optic nerve, 68 

anatomy of, 68 
atrophy of, 155 

above primary centers, 

179 
below primary centers, 

177 
in bulbar paralysis, 158 
in cerebellar hereditary 

ataxia, 159 
characteristics of, 155 
in chronic myelitis, 158 
classifications of, 155 
consecutive, 162 
in disease of chiasm, 176 
of primary optic 

centers, 177 
of tracts, 177 
field changes in, 155 
in Friedreich's ataxia, 

159 
in glaucoma, 144 
perimetric symptoms 
present in all varieties, 
155 , < 
postneuritic, 162 
primary, 156 
scotoma in, 156 
secondary, 162 
in spastic paraplegia, 

158 . 
in syringomyelia, 158 

in tabes dorsalis, 156 

in tower skull, 169 

disease of, 144 

environment of, 144 

papillomacular bundle of, 

70 

neuritis, 145 



Optic neuritis, field changes in, 145 
varieties, 145 
radiations, 74 

color anopsias in disease of, 

183 
crossed amblyopia in disease 

of, 180 
disease of, 182 
fields in disease of, 182 
hemianopsia in, 182 
thalamus, 72 

fields in disease of, 179 
tracts, 72 

fields in disease of, 177 
Outer neuron of retina, 67 

blood supply of, 67 



Papilledema, 135. See Papillitis. 
Papillitis, 134 

binasal quadrant defects in, 137 
enlarged blind spot in, 134, 135 
field changes in 134, 135, 137, 163 
hemianopsia in, 136, 137 
reversal of color fields in, 136 
scotoma in, 135 
Papillomacular bundle, 70 

disease of, in toxic ambly- 
opia, 151 
position of, in optic nerve, 70 
shape of, 71 
Paralysis agitans, fields in, 158 
Paresis, 157 

field changes in, 157 
scotoma in, 157 
Pathology, general, of fields, 82 

of form and color fields, 
94 
special, 102 
Perimeter, 55 

artificially lighted, 60 
bedside, 59 

Schweiggers's, 60 
Forster's, 56 
hand, 59 

Holth's chord, 60 
measuring strabismus on, 208 
modern examples of, 57 
Reber's umbrella, 58 
self-registering, 56 
Perineuritis, 145 
Peripheral field changes, 94 

in chiasmal disease, 16S 
in choroiditis, 104 
in disease of optic radia- 
tion, 182 
of pituitary body, 
168 
in glaucoma, 138 
in optic atrophy, 155 
in retinitis, 107, 118 
in tract disease, 177 



INDEX 



231 



Physiology of vision. 76 

of physicochemical phase, 76 
of physiologic phase, 79 
of psychologic phase, 80 
Pituitary disease, fields in, 168 

hemianopsia in, 168, 169 
binasal, 169 
bitemporal, 169 
Positive scotoma, 84 

in choroiditis, 104 
in chronic nephritis, 111 
in migraine, 200 
Postneuritic atrophy, 162 

fields in, 163 
Practical use of campimeter, 40, 41 
Primary optic atrophy, 155 

field changes in, 156 
scotoma in, 156 
centers, 72 

communication with 
motor oculi centers, 
73 
disease of, 177 

field changes in, 
178 
Prism phenomenon of Wilbrand, 

178_ 
Psychic blindness, 81 
Pulvinar, disease of, 179 
Pupillarv phenomenon of Wernicke, 

178 
Pyrotechnic display of lights in mi- 
graine, 202 



Q 



Quadrant anopsia, 89 

in cortical lesions, 185 
in migraine, 205 
in pituitary disease, 176 
scotoma, 89 
Qualitative color changes, 43, 45 
Quantitative color changes, 43, 45 



Reber's four-point method of central 
fixation, 46 
umbrella perimeter, 58 
Recording of fields on a non-register- 
ing perimeter, 63 
Remote hemorrhages, fields in, 

130 
Retina, anatomy of, 66 
blood supply 01^7 
blue-blindness in, 122 
detachment of, 121 
distribution of nerve elements, 

67 
rod and cone lair of, 77 
Retinitis, 107 

color changes in, 107 



Retinitis, diabetic, 114 

field changes in, 107-118 
of Hodgkin's disease, 115 
leukemic, 114 
nephritic, 111 

enlargement of blind spot in, 

112, 114 
fields in, 111 
of pernicious anemia, 115 
pigmentosa, 118 

central vision in, 118 
color fields in, 118 
form field in, 118 
ring scotoma in, 119, 120 
syphilitic form of, 121 
of pregnancy, 112 
scotomata in, 108 
solar and electric, 115 
syphilitic, 110 
fields in, 110 
Retrobulbar neuritis, acute, 150 
field changes, 151 
central scotoma, 152 
chronic, 151 

enlarged blind spot in. 
153 
Reversal of color fields in brain tumor, 
136 
in hysteria, 195 
Ring scotoma, 86 

formation of, 87 

in choroiditis, 104 
in commotio retinae, 124 
location of, 87 
in migraine, 204 
in nephritic retinitis, 111 
in retinitis, 108 

pigmentosa, 120 
in solar retinitis, 115 
Rods and cones, distribution of, 67 
Rupture of choroid and retina, 126 



Schlosser's method of fixation in 

central scotoma, 46 
Scotoma, 82 

absolute, 82 

in accessory sinus disease, 148 
in antrum disease, 148 
associated with peripheral field 

changes, 93 
Bjerrum's, in glaucoma, 142 
central, 85 

binocular, 46 
fixation in, 46 

Hess' method, 46 
practical method. 47 
Reber's four-point 

method, 46 
Schlosser's method. 46 
von Szily's method, 46 
hemianopic, 89 



232 



INDEX 



Scotoma, central, hemianopic, line of 
demarcation, 90 
in Leber's disease, 160 
in toxic amblyopia, 152 
in choroiditis, 104, 165 
in commotio retinae, 124 
in crossed amblyopia, 180 
in ethmoid disease, 148 
examination of, 43 

Bjerrum's method, 44 
on campimeter, 43 
Peter's method, 45 
in frontal sinusitis, 148 
in glaucoma, 141 
indistinct, 83 
in insular sclerosis, 57 
negative, 84 
paracentral, 85 
in paresis, 157 
pericentral, 85 
peripheral, 85 
positive, 84 

how formed, 84 
significance of, 84 
in primary optic atrophy, 156 
quadrant, 89 
relative, 82 
in retinitis, 108, 165 
diabetic, 114 
nephritica, 111 
syphilitica, 110 
solar and electric, 115 
sphenoidal disease, 148 
ring, 86 

in commotio retinae, 88 
formation of, 87 
in migraine, 204 
in retinitis, 88 

pigmentosa, 120 
solar, 115 
scintillating, 101, 200 
with choked disc, 94 
with field changes, 93 
with hysteria, 94 
Scotometer, Bardsley's, 61 
Berry-Hoycroft's, 61 
Priestley Smith's, 61 
Secondary atrophy, 162 

field changes in, 162 
Shape of normal form field, 22 
Sinusitis, antral, 148 
blind spot in, 149 
ethmoidal, 148 
field changes in, 149 
frontal, 148 
sphenoidal, 148 
Size of normal form field, 22 
Snellen's test type for taking central 

vision, 19 
Spastic paraplegia, 158 
Special pathology of fields, 102 
Spiral field, 197 

Stereoscopic cords of Haetz, 46 
fixation, 46 



Sympathetic amblyopia of Fergus, 155 
Syringomyelia, fields in, 158 



Tabes dorsalis, atrophy in, 156 

field changes in, 156, 157 
Tangent perimeter, 35. See Campim- 
eter. 
Duane's curtain, 53 
Tangents, natural, for constructing 

campimeter, 38 
Test object for perimetric study, 39 

size and shape of, 39 
in Bjerrum's 
method, 44 
Thrombosis of central arterv, 127, 161 
fields in, 128, 161 
of retinal veins, 129 
Tomlinson's scotomagraph, 47 
Tower skull, 159 
Toxic amblyopia, 151 

central scotoma in, 152 
enlargement of blind spot in, 

152 
field changes in, 152, 153,. 

154, 155 
papillomacular bundle in- 
volved in, 153 
Traumatic anesthesia of retina, 126 
hole in the macula, 129 
neurosis, 190 
Tubular field, 99 

in hysteria, 194 
Types of pathologic fields, 94 



V 



Visual acuity, 18 

method of determining, 18, 19 
centers, cortical, 184 

lower, or primary optic, 177 
paths to brain, 74 
purple, 78 
Von Ruess's method of taking fatigue 

field, 197 
Von Szily's method of outlining cen- 
tral scotoma, 46 



W 



Wernicke pupillarv phenomenon, 

178 
Wilbrand's exhaustion tvpe of field, 
198 
oscillating field, 200 

value of, 178 
prism phenomenon, 178 
value of, 178 
Wounds of retina, 133 

field changes in, 133 



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